Make 0 0 0 0 = 8

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
54
down vote

favorite
5












Can you find a way to make:




$0 0 0 0 = 8$




by adding any operations or symbols? You can use only these symbols:




$+, -, *, !, /, hat, , ()$.




It is limited to this list, and concatenation is also allowed. You cannot add other numbers to the equation.










share|improve this question

















  • 37




    Just put a slash over the equal sign!
    – Yout Ried
    Sep 7 at 0:40






  • 11




    @YoutRied: standard loophole: neither funny nor creative. It's usually the first answer on any math puzzle.
    – Thomas Weller
    Sep 7 at 18:40






  • 1




    Are we allowed to move anything, or is it insert only?
    – ctrl-alt-delor
    Sep 7 at 19:33






  • 1




    Are you allowed to concatenate operators? (e.g !!, **, --, and ++)
    – Ole Tange
    Sep 9 at 1:09










  • @OleTange The accepted answer does concatenate operators. Also, the question allows it.
    – haykam
    Sep 9 at 13:59














up vote
54
down vote

favorite
5












Can you find a way to make:




$0 0 0 0 = 8$




by adding any operations or symbols? You can use only these symbols:




$+, -, *, !, /, hat, , ()$.




It is limited to this list, and concatenation is also allowed. You cannot add other numbers to the equation.










share|improve this question

















  • 37




    Just put a slash over the equal sign!
    – Yout Ried
    Sep 7 at 0:40






  • 11




    @YoutRied: standard loophole: neither funny nor creative. It's usually the first answer on any math puzzle.
    – Thomas Weller
    Sep 7 at 18:40






  • 1




    Are we allowed to move anything, or is it insert only?
    – ctrl-alt-delor
    Sep 7 at 19:33






  • 1




    Are you allowed to concatenate operators? (e.g !!, **, --, and ++)
    – Ole Tange
    Sep 9 at 1:09










  • @OleTange The accepted answer does concatenate operators. Also, the question allows it.
    – haykam
    Sep 9 at 13:59












up vote
54
down vote

favorite
5









up vote
54
down vote

favorite
5






5





Can you find a way to make:




$0 0 0 0 = 8$




by adding any operations or symbols? You can use only these symbols:




$+, -, *, !, /, hat, , ()$.




It is limited to this list, and concatenation is also allowed. You cannot add other numbers to the equation.










share|improve this question













Can you find a way to make:




$0 0 0 0 = 8$




by adding any operations or symbols? You can use only these symbols:




$+, -, *, !, /, hat, , ()$.




It is limited to this list, and concatenation is also allowed. You cannot add other numbers to the equation.







mathematics number-theory






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Sep 7 at 0:35









kraby15

2,3393730




2,3393730







  • 37




    Just put a slash over the equal sign!
    – Yout Ried
    Sep 7 at 0:40






  • 11




    @YoutRied: standard loophole: neither funny nor creative. It's usually the first answer on any math puzzle.
    – Thomas Weller
    Sep 7 at 18:40






  • 1




    Are we allowed to move anything, or is it insert only?
    – ctrl-alt-delor
    Sep 7 at 19:33






  • 1




    Are you allowed to concatenate operators? (e.g !!, **, --, and ++)
    – Ole Tange
    Sep 9 at 1:09










  • @OleTange The accepted answer does concatenate operators. Also, the question allows it.
    – haykam
    Sep 9 at 13:59












  • 37




    Just put a slash over the equal sign!
    – Yout Ried
    Sep 7 at 0:40






  • 11




    @YoutRied: standard loophole: neither funny nor creative. It's usually the first answer on any math puzzle.
    – Thomas Weller
    Sep 7 at 18:40






  • 1




    Are we allowed to move anything, or is it insert only?
    – ctrl-alt-delor
    Sep 7 at 19:33






  • 1




    Are you allowed to concatenate operators? (e.g !!, **, --, and ++)
    – Ole Tange
    Sep 9 at 1:09










  • @OleTange The accepted answer does concatenate operators. Also, the question allows it.
    – haykam
    Sep 9 at 13:59







37




37




Just put a slash over the equal sign!
– Yout Ried
Sep 7 at 0:40




Just put a slash over the equal sign!
– Yout Ried
Sep 7 at 0:40




11




11




@YoutRied: standard loophole: neither funny nor creative. It's usually the first answer on any math puzzle.
– Thomas Weller
Sep 7 at 18:40




@YoutRied: standard loophole: neither funny nor creative. It's usually the first answer on any math puzzle.
– Thomas Weller
Sep 7 at 18:40




1




1




Are we allowed to move anything, or is it insert only?
– ctrl-alt-delor
Sep 7 at 19:33




Are we allowed to move anything, or is it insert only?
– ctrl-alt-delor
Sep 7 at 19:33




1




1




Are you allowed to concatenate operators? (e.g !!, **, --, and ++)
– Ole Tange
Sep 9 at 1:09




Are you allowed to concatenate operators? (e.g !!, **, --, and ++)
– Ole Tange
Sep 9 at 1:09












@OleTange The accepted answer does concatenate operators. Also, the question allows it.
– haykam
Sep 9 at 13:59




@OleTange The accepted answer does concatenate operators. Also, the question allows it.
– haykam
Sep 9 at 13:59










24 Answers
24






active

oldest

votes

















up vote
94
down vote



accepted










I think that




$left( 0! + 0! + 0! + 0! right)!! = 8$.




This is because




$0! = 1$ and $4!! = 8$. Note that $left( 0! + 0! + 0! + 0! right)!! = left( 1+1+1+1 right)!! = left (4 right)!! = 8$.




This works and is valid because




The question says I’m allowed to use any of the following symbols in my answer, I am not restricted to using $!$ as an operation only.







share|improve this answer


















  • 62




    for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
    – casualcoder
    Sep 7 at 7:16







  • 11




    @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
    – user477343
    Sep 7 at 11:49







  • 3




    @casualcoder Google disagrees with Wolfram on this.
    – user1717828
    Sep 7 at 14:46







  • 10




    Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
    – AlexanderJ93
    Sep 7 at 23:03






  • 2




    @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
    – El-Guest
    Sep 7 at 23:09

















up vote
98
down vote













A lateral thinking answer:




0! 0 0 0, because the binary equivalent of 8 is 1000 :)







share|improve this answer


















  • 7




    I like this! very direct and minimal.
    – Ruadhan2300
    Sep 7 at 14:25






  • 1




    My favourite one! I did wonder if someone would go binary.
    – oliver-clare
    Sep 7 at 15:07










  • I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
    – Stilez
    Sep 10 at 8:24


















up vote
69
down vote














$0 + 0 + 0 + 0 ~~!!=~ 8$




because




$ !!= $ is an alternative way of writing $ ne $.







share|improve this answer
















  • 4




    This is the answer!
    – Theodore Weld
    Sep 8 at 2:20






  • 3




    @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
    – phuclv
    Sep 8 at 4:24


















up vote
55
down vote













Lateral thinking!




$$0+0+substack0\0=0+0+8=8$$







share|improve this answer
















  • 8




    First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
    – Fabian Röling
    Sep 7 at 12:01






  • 79




    Looks more like vertical thinking to me.
    – Evargalo
    Sep 7 at 12:02

















up vote
34
down vote













let me try:




$0! Vert 0 - 0!-0! =8$

$10-1-1=8$


$Vert$ is a concatenation operation







share|improve this answer


















  • 1




    good solution but in this case you cant use '[' or ']'
    – casualcoder
    Sep 7 at 7:13






  • 3




    @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
    – Zizy Archer
    Sep 7 at 7:51






  • 1




    I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
    – user477343
    Sep 7 at 11:53







  • 2




    I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
    – Chronocidal
    Sep 7 at 14:22






  • 3




    @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
    – kasperd
    Sep 8 at 12:20

















up vote
27
down vote














$((0!+0!)^(0!+0!))!!$




Evaluation:




$((0!+0!)^(0!+0!))!!$

$rightarrow ((1+1)^(1+1))!!$

$rightarrow (2^2)!!$

$rightarrow 4!! = 8$







share|improve this answer



























    up vote
    27
    down vote













    It's different:




    $,++$

    $0;;;0$

    $,++$

    $0;;;0$

    $,++$


    An ASCII art $8$ using only four $0$'s and $+$'s.







    share|improve this answer



























      up vote
      16
      down vote














      0 + 0 + 0 + 0 = !8




      because




      In C/C++, ! refers to the logical not operator, where all non-zero values become 0, and 0 becomes 1.







      share|improve this answer




















      • I think this should be "the binary not operator".
        – Raimund Krämer
        Sep 11 at 8:17






      • 3




        @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
        – Jens
        Sep 11 at 15:56










      • But !8 can be a subfactorial of 8.
        – rus9384
        Sep 12 at 11:39










      • @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
        – ikegami
        Sep 13 at 11:12











      • @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
        – l k
        2 days ago

















      up vote
      14
      down vote













      It's just a matter of perspective ...




      0!/0 + 0!/0 = ∞




      My reasoning....




      0/0 is undefined so we have to first change the 0's into 1's with 0!

      (...and why did you write the infinity symbol sideways in your question?)







      share|improve this answer


















      • 1




        x/0 isn't infinite, though...
        – Adam Smith
        Sep 8 at 17:49










      • Lateral thinking was yesterday. Vertical thinking is the new kid in town!
        – Jens
        Sep 11 at 15:59






      • 1




        x/0 == +infinity, per ieee 754
        – j__m
        Sep 15 at 12:40

















      up vote
      10
      down vote














      $$[+!0]+[0]-!0-!0$$




      Works in JavaScript. Hit F12 and type this into the console (This equation editor uses "−" instead of "-" so copy and paste doesn't quite work). Otherwise, it works in the same way as @malioboro and @Arnaldur's answers.



      In fact, you can make any JavaScript application run just by using a combination of 6 characters, which is what inspired me to make this. I substituted + for 0 when asking JSF**k to do 10-2.






      share|improve this answer
















      • 3




        I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
        – Ross Presser
        Sep 8 at 4:10






      • 2




        but the question is tagged mathematics and not programming
        – phuclv
        Sep 8 at 4:21







      • 3




        Who says you can use square brackets....
        – user52269
        Sep 8 at 6:57

















      up vote
      8
      down vote














      $concat(0!,0) - 0! - 0! = 8$




      becomes:




      $concat(1,0) - 1 - 1 = 8$




      and finally:




      $10 - 2 = 8$




      cool puzzle!






      share|improve this answer
















      • 2




        Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
        – user477343
        Sep 7 at 7:44


















      up vote
      7
      down vote














      $0 + 0 + 0 + 0 equiv 8$



      Adding the symbol $-$ over the equals sign makes it a congruence sign.
      Considering the congruence relation, we must be working mod N, where N divides 8.







      share|improve this answer



























        up vote
        3
        down vote














        Just put the minus symbol over the first zero to give it the look of a figure 8 and use plus to add the zeros.







        share|improve this answer




















        • Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
          – user477343
          Sep 7 at 11:51







        • 2




          @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
          – Fabian Röling
          Sep 7 at 12:02










        • @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
          – user477343
          Sep 7 at 12:09







        • 3




          @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
          – Jaap Scherphuis
          Sep 7 at 12:55






        • 1




          Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
          – Sentinel
          Sep 7 at 14:44

















        up vote
        3
        down vote













        Here is an answer that doesn't use the semi-factorial or any concatenation.




        $$0 + 0 - 0! / 0 = (-8)!$$




        The left side is $-1/0$ and the right side is $-infty$.




        Plugging the expression into Wolfram.






        share|improve this answer
















        • 4




          Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
          – dr jimbob
          Sep 8 at 18:11

















        up vote
        2
        down vote













        Question limits the symbols, not the operations. So with the symbol + can make the operator ++.




        (++(++(++(++(++(++(++0000))))))) = 8







        share|improve this answer






















        • I think you'd need the prefix form if you actually wanted that to work.
          – LegionMammal978
          Sep 7 at 23:48






        • 1




          Doh. Of course you can't increment a literal in the first place.
          – David Browne - Microsoft
          Sep 7 at 23:55






        • 1




          but that symbol doesn't exist in mathematics
          – phuclv
          Sep 8 at 4:20






        • 2




          You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
          – NieDzejkob
          Sep 8 at 14:35

















        up vote
        2
        down vote














        concatenate(0!, 0) - concatenate(0! + 0!) = 8.




        Note that 0! = 1




        (0!, 0) = 10, and (0! + 0!) = 2, so 10 - 2 = 8







        share|improve this answer






















        • Unfortunately concatenate is not a valid operation.
          – boboquack
          Sep 11 at 1:37










        • Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
          – Alto
          Sep 11 at 1:47










        • Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
          – Alto
          Sep 11 at 1:48

















        up vote
        2
        down vote














        Add a - above the equals to get $0000 equiv 8$, which is true assuming we are working in the ring $mathbbZ/mathbb2Z$. (Note I'm trying to avoid writing $[0] = [8]$...)







        share|improve this answer





























          up vote
          1
          down vote













          This could work too:




          (0!+0+0)/0 = ∞




          Explanation




          (0!+0+0)/0 = 1/0 which is infinity (8 but put horizontally)







          share|improve this answer



























            up vote
            0
            down vote














            $ ((0! + 0!)$)*(0! + 0!) = 2^2*2 = 8 $.




            Further explanation:




            The $$$ operation denotes the superfactorial defined as : $ n$ = (n!) uparrow uparrow (n!)$.







            share|improve this answer


















            • 3




              Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
              – Sensoray
              Sep 7 at 15:26

















            up vote
            0
            down vote













            If you turn the problem around




            enter image description here







            share|improve this answer




















            • Similar to @rrauenza's answer
              – TheSimpliFire
              Sep 8 at 8:11










            • Yes. A different way to express the same idea.
              – Florian F
              Sep 8 at 9:13

















            up vote
            0
            down vote














            As per the list of allowed symbols we are clearly allowed to use "$,$" and "$.$"

            This is doubly evident as otherwise how would we use the $mathbbconcatenation$ function without a comma to separate the arguments?




            So the solution is:




            $0! - mathbbconcatenation(., 0 + 0! + 0!!) = .8$

            $1 - mathbbconcatenation(., 0 + 1 + 1) = .8$

            $1 - mathbbconcatenation(., 2) = .8$

            $1 - .2 = .8$







            share|improve this answer




















            • You may simplify 0!! as 0!.
              – Cœur
              Sep 11 at 15:28










            • I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
              – SamYonnou
              Sep 11 at 16:58

















            up vote
            -1
            down vote














            $00^00 = 0^0$ which is indeterminate. In some sense, an indeterminate form can be equal to any value, since in Calculus, a function that approaches "$0^0$" can approach any real value, including $8$. So in that sense, $0^0 = 8$.


            If you don't like concatenating two zeroes as "$00$", then $0^0 + 0 + 0$ also works.







            share|improve this answer


















            • 7




              There are no widely accepted definitions under which your equation is considered to be true.
              – Tanner Swett
              Sep 7 at 17:34










            • @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
              – RothX
              Sep 10 at 13:23











            • Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
              – Tanner Swett
              Sep 10 at 13:59










            • @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
              – RothX
              Sep 11 at 1:58

















            up vote
            -1
            down vote













            Factorial of Zero equals to 1. And 4!!=8.
            Then you can put plus and power to end up the story.
            ((0!+0!)^(0!+0!))!!






            share|improve this answer


















            • 4




              this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
              – JonMark Perry
              Sep 8 at 7:55











            • Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
              – F1Krazy
              Sep 8 at 8:55

















            up vote
            -1
            down vote













            Similar to @Vaelus




            $0+0+0+0 leq 8$




            Explanation




            You can get the $leq$ by adding a $-$ inclined on top of the $=$







            share|improve this answer




















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              24 Answers
              24






              active

              oldest

              votes








              24 Answers
              24






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes








              up vote
              94
              down vote



              accepted










              I think that




              $left( 0! + 0! + 0! + 0! right)!! = 8$.




              This is because




              $0! = 1$ and $4!! = 8$. Note that $left( 0! + 0! + 0! + 0! right)!! = left( 1+1+1+1 right)!! = left (4 right)!! = 8$.




              This works and is valid because




              The question says I’m allowed to use any of the following symbols in my answer, I am not restricted to using $!$ as an operation only.







              share|improve this answer


















              • 62




                for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
                – casualcoder
                Sep 7 at 7:16







              • 11




                @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
                – user477343
                Sep 7 at 11:49







              • 3




                @casualcoder Google disagrees with Wolfram on this.
                – user1717828
                Sep 7 at 14:46







              • 10




                Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
                – AlexanderJ93
                Sep 7 at 23:03






              • 2




                @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
                – El-Guest
                Sep 7 at 23:09














              up vote
              94
              down vote



              accepted










              I think that




              $left( 0! + 0! + 0! + 0! right)!! = 8$.




              This is because




              $0! = 1$ and $4!! = 8$. Note that $left( 0! + 0! + 0! + 0! right)!! = left( 1+1+1+1 right)!! = left (4 right)!! = 8$.




              This works and is valid because




              The question says I’m allowed to use any of the following symbols in my answer, I am not restricted to using $!$ as an operation only.







              share|improve this answer


















              • 62




                for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
                – casualcoder
                Sep 7 at 7:16







              • 11




                @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
                – user477343
                Sep 7 at 11:49







              • 3




                @casualcoder Google disagrees with Wolfram on this.
                – user1717828
                Sep 7 at 14:46







              • 10




                Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
                – AlexanderJ93
                Sep 7 at 23:03






              • 2




                @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
                – El-Guest
                Sep 7 at 23:09












              up vote
              94
              down vote



              accepted







              up vote
              94
              down vote



              accepted






              I think that




              $left( 0! + 0! + 0! + 0! right)!! = 8$.




              This is because




              $0! = 1$ and $4!! = 8$. Note that $left( 0! + 0! + 0! + 0! right)!! = left( 1+1+1+1 right)!! = left (4 right)!! = 8$.




              This works and is valid because




              The question says I’m allowed to use any of the following symbols in my answer, I am not restricted to using $!$ as an operation only.







              share|improve this answer














              I think that




              $left( 0! + 0! + 0! + 0! right)!! = 8$.




              This is because




              $0! = 1$ and $4!! = 8$. Note that $left( 0! + 0! + 0! + 0! right)!! = left( 1+1+1+1 right)!! = left (4 right)!! = 8$.




              This works and is valid because




              The question says I’m allowed to use any of the following symbols in my answer, I am not restricted to using $!$ as an operation only.








              share|improve this answer














              share|improve this answer



              share|improve this answer








              edited Sep 7 at 6:42









              Laurel

              681310




              681310










              answered Sep 7 at 0:40









              El-Guest

              11.4k2256




              11.4k2256







              • 62




                for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
                – casualcoder
                Sep 7 at 7:16







              • 11




                @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
                – user477343
                Sep 7 at 11:49







              • 3




                @casualcoder Google disagrees with Wolfram on this.
                – user1717828
                Sep 7 at 14:46







              • 10




                Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
                – AlexanderJ93
                Sep 7 at 23:03






              • 2




                @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
                – El-Guest
                Sep 7 at 23:09












              • 62




                for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
                – casualcoder
                Sep 7 at 7:16







              • 11




                @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
                – user477343
                Sep 7 at 11:49







              • 3




                @casualcoder Google disagrees with Wolfram on this.
                – user1717828
                Sep 7 at 14:46







              • 10




                Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
                – AlexanderJ93
                Sep 7 at 23:03






              • 2




                @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
                – El-Guest
                Sep 7 at 23:09







              62




              62




              for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
              – casualcoder
              Sep 7 at 7:16





              for those who are confused, !! is a mathematical operator that gives the product of all positive integers upto the argument which have the same parity (odd/even) as the argument, its called a semifactorial. (thus 4!! is 2*4 = 8)
              – casualcoder
              Sep 7 at 7:16





              11




              11




              @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
              – user477343
              Sep 7 at 11:49





              @casualcoder most people assume $n!!$ for an arbitrary non-negative integer $n$ is the same as $(n!)!$, but it's not. That brings up some confusion, so I usually write $n!_k$ to denote $n$ with $k$ factorials, but not on this site.
              – user477343
              Sep 7 at 11:49





              3




              3




              @casualcoder Google disagrees with Wolfram on this.
              – user1717828
              Sep 7 at 14:46





              @casualcoder Google disagrees with Wolfram on this.
              – user1717828
              Sep 7 at 14:46





              10




              10




              Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
              – AlexanderJ93
              Sep 7 at 23:03




              Google disagrees with Wolfram on a lot of things. When it comes to math, chances are Wolfram is the correct one.
              – AlexanderJ93
              Sep 7 at 23:03




              2




              2




              @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
              – El-Guest
              Sep 7 at 23:09




              @user1717828, user477343’s comment above explains why Google’s interpretation is not correct in this context.
              – El-Guest
              Sep 7 at 23:09










              up vote
              98
              down vote













              A lateral thinking answer:




              0! 0 0 0, because the binary equivalent of 8 is 1000 :)







              share|improve this answer


















              • 7




                I like this! very direct and minimal.
                – Ruadhan2300
                Sep 7 at 14:25






              • 1




                My favourite one! I did wonder if someone would go binary.
                – oliver-clare
                Sep 7 at 15:07










              • I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
                – Stilez
                Sep 10 at 8:24















              up vote
              98
              down vote













              A lateral thinking answer:




              0! 0 0 0, because the binary equivalent of 8 is 1000 :)







              share|improve this answer


















              • 7




                I like this! very direct and minimal.
                – Ruadhan2300
                Sep 7 at 14:25






              • 1




                My favourite one! I did wonder if someone would go binary.
                – oliver-clare
                Sep 7 at 15:07










              • I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
                – Stilez
                Sep 10 at 8:24













              up vote
              98
              down vote










              up vote
              98
              down vote









              A lateral thinking answer:




              0! 0 0 0, because the binary equivalent of 8 is 1000 :)







              share|improve this answer














              A lateral thinking answer:




              0! 0 0 0, because the binary equivalent of 8 is 1000 :)








              share|improve this answer














              share|improve this answer



              share|improve this answer








              edited Sep 7 at 14:01









              El-Guest

              11.4k2256




              11.4k2256










              answered Sep 7 at 13:44









              let_the_coding_begin

              1,01114




              1,01114







              • 7




                I like this! very direct and minimal.
                – Ruadhan2300
                Sep 7 at 14:25






              • 1




                My favourite one! I did wonder if someone would go binary.
                – oliver-clare
                Sep 7 at 15:07










              • I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
                – Stilez
                Sep 10 at 8:24













              • 7




                I like this! very direct and minimal.
                – Ruadhan2300
                Sep 7 at 14:25






              • 1




                My favourite one! I did wonder if someone would go binary.
                – oliver-clare
                Sep 7 at 15:07










              • I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
                – Stilez
                Sep 10 at 8:24








              7




              7




              I like this! very direct and minimal.
              – Ruadhan2300
              Sep 7 at 14:25




              I like this! very direct and minimal.
              – Ruadhan2300
              Sep 7 at 14:25




              1




              1




              My favourite one! I did wonder if someone would go binary.
              – oliver-clare
              Sep 7 at 15:07




              My favourite one! I did wonder if someone would go binary.
              – oliver-clare
              Sep 7 at 15:07












              I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
              – Stilez
              Sep 10 at 8:24





              I was just checking existing answers to see if anyone else had thought of ! In the sense of negation, and binary. So "yes" :)
              – Stilez
              Sep 10 at 8:24











              up vote
              69
              down vote














              $0 + 0 + 0 + 0 ~~!!=~ 8$




              because




              $ !!= $ is an alternative way of writing $ ne $.







              share|improve this answer
















              • 4




                This is the answer!
                – Theodore Weld
                Sep 8 at 2:20






              • 3




                @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
                – phuclv
                Sep 8 at 4:24















              up vote
              69
              down vote














              $0 + 0 + 0 + 0 ~~!!=~ 8$




              because




              $ !!= $ is an alternative way of writing $ ne $.







              share|improve this answer
















              • 4




                This is the answer!
                – Theodore Weld
                Sep 8 at 2:20






              • 3




                @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
                – phuclv
                Sep 8 at 4:24













              up vote
              69
              down vote










              up vote
              69
              down vote










              $0 + 0 + 0 + 0 ~~!!=~ 8$




              because




              $ !!= $ is an alternative way of writing $ ne $.







              share|improve this answer













              $0 + 0 + 0 + 0 ~~!!=~ 8$




              because




              $ !!= $ is an alternative way of writing $ ne $.








              share|improve this answer












              share|improve this answer



              share|improve this answer










              answered Sep 7 at 8:43









              Teemu Piippo

              67714




              67714







              • 4




                This is the answer!
                – Theodore Weld
                Sep 8 at 2:20






              • 3




                @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
                – phuclv
                Sep 8 at 4:24













              • 4




                This is the answer!
                – Theodore Weld
                Sep 8 at 2:20






              • 3




                @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
                – phuclv
                Sep 8 at 4:24








              4




              4




              This is the answer!
              – Theodore Weld
              Sep 8 at 2:20




              This is the answer!
              – Theodore Weld
              Sep 8 at 2:20




              3




              3




              @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
              – phuclv
              Sep 8 at 4:24





              @TheodoreWeld nope, this question is tagged mathematics, and you have to use a slash similar to Yout Ried instead of this
              – phuclv
              Sep 8 at 4:24











              up vote
              55
              down vote













              Lateral thinking!




              $$0+0+substack0\0=0+0+8=8$$







              share|improve this answer
















              • 8




                First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
                – Fabian Röling
                Sep 7 at 12:01






              • 79




                Looks more like vertical thinking to me.
                – Evargalo
                Sep 7 at 12:02














              up vote
              55
              down vote













              Lateral thinking!




              $$0+0+substack0\0=0+0+8=8$$







              share|improve this answer
















              • 8




                First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
                – Fabian Röling
                Sep 7 at 12:01






              • 79




                Looks more like vertical thinking to me.
                – Evargalo
                Sep 7 at 12:02












              up vote
              55
              down vote










              up vote
              55
              down vote









              Lateral thinking!




              $$0+0+substack0\0=0+0+8=8$$







              share|improve this answer












              Lateral thinking!




              $$0+0+substack0\0=0+0+8=8$$








              share|improve this answer












              share|improve this answer



              share|improve this answer










              answered Sep 7 at 6:25









              TheSimpliFire

              1,771324




              1,771324







              • 8




                First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
                – Fabian Röling
                Sep 7 at 12:01






              • 79




                Looks more like vertical thinking to me.
                – Evargalo
                Sep 7 at 12:02












              • 8




                First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
                – Fabian Röling
                Sep 7 at 12:01






              • 79




                Looks more like vertical thinking to me.
                – Evargalo
                Sep 7 at 12:02







              8




              8




              First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
              – Fabian Röling
              Sep 7 at 12:01




              First I thought "how does picking 0 out of 0 give you 8 combinations", then I got it.
              – Fabian Röling
              Sep 7 at 12:01




              79




              79




              Looks more like vertical thinking to me.
              – Evargalo
              Sep 7 at 12:02




              Looks more like vertical thinking to me.
              – Evargalo
              Sep 7 at 12:02










              up vote
              34
              down vote













              let me try:




              $0! Vert 0 - 0!-0! =8$

              $10-1-1=8$


              $Vert$ is a concatenation operation







              share|improve this answer


















              • 1




                good solution but in this case you cant use '[' or ']'
                – casualcoder
                Sep 7 at 7:13






              • 3




                @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
                – Zizy Archer
                Sep 7 at 7:51






              • 1




                I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
                – user477343
                Sep 7 at 11:53







              • 2




                I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
                – Chronocidal
                Sep 7 at 14:22






              • 3




                @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
                – kasperd
                Sep 8 at 12:20














              up vote
              34
              down vote













              let me try:




              $0! Vert 0 - 0!-0! =8$

              $10-1-1=8$


              $Vert$ is a concatenation operation







              share|improve this answer


















              • 1




                good solution but in this case you cant use '[' or ']'
                – casualcoder
                Sep 7 at 7:13






              • 3




                @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
                – Zizy Archer
                Sep 7 at 7:51






              • 1




                I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
                – user477343
                Sep 7 at 11:53







              • 2




                I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
                – Chronocidal
                Sep 7 at 14:22






              • 3




                @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
                – kasperd
                Sep 8 at 12:20












              up vote
              34
              down vote










              up vote
              34
              down vote









              let me try:




              $0! Vert 0 - 0!-0! =8$

              $10-1-1=8$


              $Vert$ is a concatenation operation







              share|improve this answer














              let me try:




              $0! Vert 0 - 0!-0! =8$

              $10-1-1=8$


              $Vert$ is a concatenation operation








              share|improve this answer














              share|improve this answer



              share|improve this answer








              edited Sep 8 at 15:29

























              answered Sep 7 at 0:43









              malioboro

              2,295827




              2,295827







              • 1




                good solution but in this case you cant use '[' or ']'
                – casualcoder
                Sep 7 at 7:13






              • 3




                @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
                – Zizy Archer
                Sep 7 at 7:51






              • 1




                I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
                – user477343
                Sep 7 at 11:53







              • 2




                I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
                – Chronocidal
                Sep 7 at 14:22






              • 3




                @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
                – kasperd
                Sep 8 at 12:20












              • 1




                good solution but in this case you cant use '[' or ']'
                – casualcoder
                Sep 7 at 7:13






              • 3




                @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
                – Zizy Archer
                Sep 7 at 7:51






              • 1




                I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
                – user477343
                Sep 7 at 11:53







              • 2




                I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
                – Chronocidal
                Sep 7 at 14:22






              • 3




                @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
                – kasperd
                Sep 8 at 12:20







              1




              1




              good solution but in this case you cant use '[' or ']'
              – casualcoder
              Sep 7 at 7:13




              good solution but in this case you cant use '[' or ']'
              – casualcoder
              Sep 7 at 7:13




              3




              3




              @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
              – Zizy Archer
              Sep 7 at 7:51




              @casualcoder It was explicitly allowed. If this wasn't meant to be a valid solution, why even allow it, as 00 = 0+0 = 0?
              – Zizy Archer
              Sep 7 at 7:51




              1




              1




              I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
              – user477343
              Sep 7 at 11:53





              I've never used $[ldots ]$ as an operator before, let alone for what you use it as in this answer. I usually use it as a set notation; i.e., $[n]=1,2,ldots n$ :P
              – user477343
              Sep 7 at 11:53





              2




              2




              I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
              – Chronocidal
              Sep 7 at 14:22




              I think "concatenation allowed" in these puzzles usually means that, for example, 2 8 7 can be 28 ÷ 7 = 4, but not (2+8)7 = 107
              – Chronocidal
              Sep 7 at 14:22




              3




              3




              @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
              – kasperd
              Sep 8 at 12:20




              @Chronocidal What you are saying is probably true about most of these puzzles. But in this particular puzzle where all the digits are 0, that interpretation does not make a lot of sense. To me this answer feels more legitimate than the accepted answer. That's because concatenation is explicitly allowed, but the !! is not explicitly allowed (though it may be implied).
              – kasperd
              Sep 8 at 12:20










              up vote
              27
              down vote














              $((0!+0!)^(0!+0!))!!$




              Evaluation:




              $((0!+0!)^(0!+0!))!!$

              $rightarrow ((1+1)^(1+1))!!$

              $rightarrow (2^2)!!$

              $rightarrow 4!! = 8$







              share|improve this answer
























                up vote
                27
                down vote














                $((0!+0!)^(0!+0!))!!$




                Evaluation:




                $((0!+0!)^(0!+0!))!!$

                $rightarrow ((1+1)^(1+1))!!$

                $rightarrow (2^2)!!$

                $rightarrow 4!! = 8$







                share|improve this answer






















                  up vote
                  27
                  down vote










                  up vote
                  27
                  down vote










                  $((0!+0!)^(0!+0!))!!$




                  Evaluation:




                  $((0!+0!)^(0!+0!))!!$

                  $rightarrow ((1+1)^(1+1))!!$

                  $rightarrow (2^2)!!$

                  $rightarrow 4!! = 8$







                  share|improve this answer













                  $((0!+0!)^(0!+0!))!!$




                  Evaluation:




                  $((0!+0!)^(0!+0!))!!$

                  $rightarrow ((1+1)^(1+1))!!$

                  $rightarrow (2^2)!!$

                  $rightarrow 4!! = 8$








                  share|improve this answer












                  share|improve this answer



                  share|improve this answer










                  answered Sep 7 at 14:04









                  u_ndefined

                  2,140332




                  2,140332




















                      up vote
                      27
                      down vote













                      It's different:




                      $,++$

                      $0;;;0$

                      $,++$

                      $0;;;0$

                      $,++$


                      An ASCII art $8$ using only four $0$'s and $+$'s.







                      share|improve this answer
























                        up vote
                        27
                        down vote













                        It's different:




                        $,++$

                        $0;;;0$

                        $,++$

                        $0;;;0$

                        $,++$


                        An ASCII art $8$ using only four $0$'s and $+$'s.







                        share|improve this answer






















                          up vote
                          27
                          down vote










                          up vote
                          27
                          down vote









                          It's different:




                          $,++$

                          $0;;;0$

                          $,++$

                          $0;;;0$

                          $,++$


                          An ASCII art $8$ using only four $0$'s and $+$'s.







                          share|improve this answer












                          It's different:




                          $,++$

                          $0;;;0$

                          $,++$

                          $0;;;0$

                          $,++$


                          An ASCII art $8$ using only four $0$'s and $+$'s.








                          share|improve this answer












                          share|improve this answer



                          share|improve this answer










                          answered Sep 7 at 14:46









                          JonMark Perry

                          14.7k52972




                          14.7k52972




















                              up vote
                              16
                              down vote














                              0 + 0 + 0 + 0 = !8




                              because




                              In C/C++, ! refers to the logical not operator, where all non-zero values become 0, and 0 becomes 1.







                              share|improve this answer




















                              • I think this should be "the binary not operator".
                                – Raimund Krämer
                                Sep 11 at 8:17






                              • 3




                                @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
                                – Jens
                                Sep 11 at 15:56










                              • But !8 can be a subfactorial of 8.
                                – rus9384
                                Sep 12 at 11:39










                              • @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
                                – ikegami
                                Sep 13 at 11:12











                              • @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
                                – l k
                                2 days ago














                              up vote
                              16
                              down vote














                              0 + 0 + 0 + 0 = !8




                              because




                              In C/C++, ! refers to the logical not operator, where all non-zero values become 0, and 0 becomes 1.







                              share|improve this answer




















                              • I think this should be "the binary not operator".
                                – Raimund Krämer
                                Sep 11 at 8:17






                              • 3




                                @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
                                – Jens
                                Sep 11 at 15:56










                              • But !8 can be a subfactorial of 8.
                                – rus9384
                                Sep 12 at 11:39










                              • @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
                                – ikegami
                                Sep 13 at 11:12











                              • @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
                                – l k
                                2 days ago












                              up vote
                              16
                              down vote










                              up vote
                              16
                              down vote










                              0 + 0 + 0 + 0 = !8




                              because




                              In C/C++, ! refers to the logical not operator, where all non-zero values become 0, and 0 becomes 1.







                              share|improve this answer













                              0 + 0 + 0 + 0 = !8




                              because




                              In C/C++, ! refers to the logical not operator, where all non-zero values become 0, and 0 becomes 1.








                              share|improve this answer












                              share|improve this answer



                              share|improve this answer










                              answered Sep 7 at 22:48









                              l k

                              1612




                              1612











                              • I think this should be "the binary not operator".
                                – Raimund Krämer
                                Sep 11 at 8:17






                              • 3




                                @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
                                – Jens
                                Sep 11 at 15:56










                              • But !8 can be a subfactorial of 8.
                                – rus9384
                                Sep 12 at 11:39










                              • @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
                                – ikegami
                                Sep 13 at 11:12











                              • @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
                                – l k
                                2 days ago
















                              • I think this should be "the binary not operator".
                                – Raimund Krämer
                                Sep 11 at 8:17






                              • 3




                                @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
                                – Jens
                                Sep 11 at 15:56










                              • But !8 can be a subfactorial of 8.
                                – rus9384
                                Sep 12 at 11:39










                              • @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
                                – ikegami
                                Sep 13 at 11:12











                              • @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
                                – l k
                                2 days ago















                              I think this should be "the binary not operator".
                              – Raimund Krämer
                              Sep 11 at 8:17




                              I think this should be "the binary not operator".
                              – Raimund Krämer
                              Sep 11 at 8:17




                              3




                              3




                              @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
                              – Jens
                              Sep 11 at 15:56




                              @RaimundKrämer ITYM unary not. C99 calls it the "logical negation operator" and files it in the chapter "Unary operators".
                              – Jens
                              Sep 11 at 15:56












                              But !8 can be a subfactorial of 8.
                              – rus9384
                              Sep 12 at 11:39




                              But !8 can be a subfactorial of 8.
                              – rus9384
                              Sep 12 at 11:39












                              @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
                              – ikegami
                              Sep 13 at 11:12





                              @Raimund Krämer, In programming, we have logical operators and bitwise operators. Logical operators (!, &&, || in C) operate on boolean values (true and false). Bitwise operators (~, &, |, ^ in C) operate on bits (0 and 1) of numbers. Calling either set binary operators would be confusing, as both set work on binary values.
                              – ikegami
                              Sep 13 at 11:12













                              @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
                              – l k
                              2 days ago




                              @Raimund Krämer Also, "binary operator" can mean any operator on 2 values (as opposed to a unary operator such as ! or ~)
                              – l k
                              2 days ago










                              up vote
                              14
                              down vote













                              It's just a matter of perspective ...




                              0!/0 + 0!/0 = ∞




                              My reasoning....




                              0/0 is undefined so we have to first change the 0's into 1's with 0!

                              (...and why did you write the infinity symbol sideways in your question?)







                              share|improve this answer


















                              • 1




                                x/0 isn't infinite, though...
                                – Adam Smith
                                Sep 8 at 17:49










                              • Lateral thinking was yesterday. Vertical thinking is the new kid in town!
                                – Jens
                                Sep 11 at 15:59






                              • 1




                                x/0 == +infinity, per ieee 754
                                – j__m
                                Sep 15 at 12:40














                              up vote
                              14
                              down vote













                              It's just a matter of perspective ...




                              0!/0 + 0!/0 = ∞




                              My reasoning....




                              0/0 is undefined so we have to first change the 0's into 1's with 0!

                              (...and why did you write the infinity symbol sideways in your question?)







                              share|improve this answer


















                              • 1




                                x/0 isn't infinite, though...
                                – Adam Smith
                                Sep 8 at 17:49










                              • Lateral thinking was yesterday. Vertical thinking is the new kid in town!
                                – Jens
                                Sep 11 at 15:59






                              • 1




                                x/0 == +infinity, per ieee 754
                                – j__m
                                Sep 15 at 12:40












                              up vote
                              14
                              down vote










                              up vote
                              14
                              down vote









                              It's just a matter of perspective ...




                              0!/0 + 0!/0 = ∞




                              My reasoning....




                              0/0 is undefined so we have to first change the 0's into 1's with 0!

                              (...and why did you write the infinity symbol sideways in your question?)







                              share|improve this answer














                              It's just a matter of perspective ...




                              0!/0 + 0!/0 = ∞




                              My reasoning....




                              0/0 is undefined so we have to first change the 0's into 1's with 0!

                              (...and why did you write the infinity symbol sideways in your question?)








                              share|improve this answer














                              share|improve this answer



                              share|improve this answer








                              edited Sep 8 at 19:31

























                              answered Sep 7 at 18:20









                              rrauenza

                              2494




                              2494







                              • 1




                                x/0 isn't infinite, though...
                                – Adam Smith
                                Sep 8 at 17:49










                              • Lateral thinking was yesterday. Vertical thinking is the new kid in town!
                                – Jens
                                Sep 11 at 15:59






                              • 1




                                x/0 == +infinity, per ieee 754
                                – j__m
                                Sep 15 at 12:40












                              • 1




                                x/0 isn't infinite, though...
                                – Adam Smith
                                Sep 8 at 17:49










                              • Lateral thinking was yesterday. Vertical thinking is the new kid in town!
                                – Jens
                                Sep 11 at 15:59






                              • 1




                                x/0 == +infinity, per ieee 754
                                – j__m
                                Sep 15 at 12:40







                              1




                              1




                              x/0 isn't infinite, though...
                              – Adam Smith
                              Sep 8 at 17:49




                              x/0 isn't infinite, though...
                              – Adam Smith
                              Sep 8 at 17:49












                              Lateral thinking was yesterday. Vertical thinking is the new kid in town!
                              – Jens
                              Sep 11 at 15:59




                              Lateral thinking was yesterday. Vertical thinking is the new kid in town!
                              – Jens
                              Sep 11 at 15:59




                              1




                              1




                              x/0 == +infinity, per ieee 754
                              – j__m
                              Sep 15 at 12:40




                              x/0 == +infinity, per ieee 754
                              – j__m
                              Sep 15 at 12:40










                              up vote
                              10
                              down vote














                              $$[+!0]+[0]-!0-!0$$




                              Works in JavaScript. Hit F12 and type this into the console (This equation editor uses "−" instead of "-" so copy and paste doesn't quite work). Otherwise, it works in the same way as @malioboro and @Arnaldur's answers.



                              In fact, you can make any JavaScript application run just by using a combination of 6 characters, which is what inspired me to make this. I substituted + for 0 when asking JSF**k to do 10-2.






                              share|improve this answer
















                              • 3




                                I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
                                – Ross Presser
                                Sep 8 at 4:10






                              • 2




                                but the question is tagged mathematics and not programming
                                – phuclv
                                Sep 8 at 4:21







                              • 3




                                Who says you can use square brackets....
                                – user52269
                                Sep 8 at 6:57














                              up vote
                              10
                              down vote














                              $$[+!0]+[0]-!0-!0$$




                              Works in JavaScript. Hit F12 and type this into the console (This equation editor uses "−" instead of "-" so copy and paste doesn't quite work). Otherwise, it works in the same way as @malioboro and @Arnaldur's answers.



                              In fact, you can make any JavaScript application run just by using a combination of 6 characters, which is what inspired me to make this. I substituted + for 0 when asking JSF**k to do 10-2.






                              share|improve this answer
















                              • 3




                                I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
                                – Ross Presser
                                Sep 8 at 4:10






                              • 2




                                but the question is tagged mathematics and not programming
                                – phuclv
                                Sep 8 at 4:21







                              • 3




                                Who says you can use square brackets....
                                – user52269
                                Sep 8 at 6:57












                              up vote
                              10
                              down vote










                              up vote
                              10
                              down vote










                              $$[+!0]+[0]-!0-!0$$




                              Works in JavaScript. Hit F12 and type this into the console (This equation editor uses "−" instead of "-" so copy and paste doesn't quite work). Otherwise, it works in the same way as @malioboro and @Arnaldur's answers.



                              In fact, you can make any JavaScript application run just by using a combination of 6 characters, which is what inspired me to make this. I substituted + for 0 when asking JSF**k to do 10-2.






                              share|improve this answer













                              $$[+!0]+[0]-!0-!0$$




                              Works in JavaScript. Hit F12 and type this into the console (This equation editor uses "−" instead of "-" so copy and paste doesn't quite work). Otherwise, it works in the same way as @malioboro and @Arnaldur's answers.



                              In fact, you can make any JavaScript application run just by using a combination of 6 characters, which is what inspired me to make this. I substituted + for 0 when asking JSF**k to do 10-2.







                              share|improve this answer












                              share|improve this answer



                              share|improve this answer










                              answered Sep 7 at 12:35









                              Namyts

                              4445




                              4445







                              • 3




                                I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
                                – Ross Presser
                                Sep 8 at 4:10






                              • 2




                                but the question is tagged mathematics and not programming
                                – phuclv
                                Sep 8 at 4:21







                              • 3




                                Who says you can use square brackets....
                                – user52269
                                Sep 8 at 6:57












                              • 3




                                I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
                                – Ross Presser
                                Sep 8 at 4:10






                              • 2




                                but the question is tagged mathematics and not programming
                                – phuclv
                                Sep 8 at 4:21







                              • 3




                                Who says you can use square brackets....
                                – user52269
                                Sep 8 at 6:57







                              3




                              3




                              I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
                              – Ross Presser
                              Sep 8 at 4:10




                              I like this abuse of javascript a lot. !0 for true, +!0 for 1, [1] for array containing 1, [1]+[0] for concatenate two arrays to get the string "10" ; subtract 1 from that twice to end up as 8. Love it.
                              – Ross Presser
                              Sep 8 at 4:10




                              2




                              2




                              but the question is tagged mathematics and not programming
                              – phuclv
                              Sep 8 at 4:21





                              but the question is tagged mathematics and not programming
                              – phuclv
                              Sep 8 at 4:21





                              3




                              3




                              Who says you can use square brackets....
                              – user52269
                              Sep 8 at 6:57




                              Who says you can use square brackets....
                              – user52269
                              Sep 8 at 6:57










                              up vote
                              8
                              down vote














                              $concat(0!,0) - 0! - 0! = 8$




                              becomes:




                              $concat(1,0) - 1 - 1 = 8$




                              and finally:




                              $10 - 2 = 8$




                              cool puzzle!






                              share|improve this answer
















                              • 2




                                Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
                                – user477343
                                Sep 7 at 7:44















                              up vote
                              8
                              down vote














                              $concat(0!,0) - 0! - 0! = 8$




                              becomes:




                              $concat(1,0) - 1 - 1 = 8$




                              and finally:




                              $10 - 2 = 8$




                              cool puzzle!






                              share|improve this answer
















                              • 2




                                Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
                                – user477343
                                Sep 7 at 7:44













                              up vote
                              8
                              down vote










                              up vote
                              8
                              down vote










                              $concat(0!,0) - 0! - 0! = 8$




                              becomes:




                              $concat(1,0) - 1 - 1 = 8$




                              and finally:




                              $10 - 2 = 8$




                              cool puzzle!






                              share|improve this answer













                              $concat(0!,0) - 0! - 0! = 8$




                              becomes:




                              $concat(1,0) - 1 - 1 = 8$




                              and finally:




                              $10 - 2 = 8$




                              cool puzzle!







                              share|improve this answer












                              share|improve this answer



                              share|improve this answer










                              answered Sep 7 at 5:38









                              Arnaldur

                              971




                              971







                              • 2




                                Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
                                – user477343
                                Sep 7 at 7:44













                              • 2




                                Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
                                – user477343
                                Sep 7 at 7:44








                              2




                              2




                              Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
                              – user477343
                              Sep 7 at 7:44





                              Great answer! But it has already been answered (check out @malioboro 's answer). Nonetheless, welcome to the Puzzling Stack Exchange (Puzzling.SE)! Since you are new to the Stack Exchange community, let alone this site, I strongly suggest that you visit the Help Center for more info; in particular, I suggest going here, then here for questions (not answers) :D
                              – user477343
                              Sep 7 at 7:44











                              up vote
                              7
                              down vote














                              $0 + 0 + 0 + 0 equiv 8$



                              Adding the symbol $-$ over the equals sign makes it a congruence sign.
                              Considering the congruence relation, we must be working mod N, where N divides 8.







                              share|improve this answer
























                                up vote
                                7
                                down vote














                                $0 + 0 + 0 + 0 equiv 8$



                                Adding the symbol $-$ over the equals sign makes it a congruence sign.
                                Considering the congruence relation, we must be working mod N, where N divides 8.







                                share|improve this answer






















                                  up vote
                                  7
                                  down vote










                                  up vote
                                  7
                                  down vote










                                  $0 + 0 + 0 + 0 equiv 8$



                                  Adding the symbol $-$ over the equals sign makes it a congruence sign.
                                  Considering the congruence relation, we must be working mod N, where N divides 8.







                                  share|improve this answer













                                  $0 + 0 + 0 + 0 equiv 8$



                                  Adding the symbol $-$ over the equals sign makes it a congruence sign.
                                  Considering the congruence relation, we must be working mod N, where N divides 8.








                                  share|improve this answer












                                  share|improve this answer



                                  share|improve this answer










                                  answered Sep 8 at 6:39









                                  Vaelus

                                  40124




                                  40124




















                                      up vote
                                      3
                                      down vote














                                      Just put the minus symbol over the first zero to give it the look of a figure 8 and use plus to add the zeros.







                                      share|improve this answer




















                                      • Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
                                        – user477343
                                        Sep 7 at 11:51







                                      • 2




                                        @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
                                        – Fabian Röling
                                        Sep 7 at 12:02










                                      • @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
                                        – user477343
                                        Sep 7 at 12:09







                                      • 3




                                        @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
                                        – Jaap Scherphuis
                                        Sep 7 at 12:55






                                      • 1




                                        Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
                                        – Sentinel
                                        Sep 7 at 14:44














                                      up vote
                                      3
                                      down vote














                                      Just put the minus symbol over the first zero to give it the look of a figure 8 and use plus to add the zeros.







                                      share|improve this answer




















                                      • Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
                                        – user477343
                                        Sep 7 at 11:51







                                      • 2




                                        @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
                                        – Fabian Röling
                                        Sep 7 at 12:02










                                      • @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
                                        – user477343
                                        Sep 7 at 12:09







                                      • 3




                                        @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
                                        – Jaap Scherphuis
                                        Sep 7 at 12:55






                                      • 1




                                        Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
                                        – Sentinel
                                        Sep 7 at 14:44












                                      up vote
                                      3
                                      down vote










                                      up vote
                                      3
                                      down vote










                                      Just put the minus symbol over the first zero to give it the look of a figure 8 and use plus to add the zeros.







                                      share|improve this answer













                                      Just put the minus symbol over the first zero to give it the look of a figure 8 and use plus to add the zeros.








                                      share|improve this answer












                                      share|improve this answer



                                      share|improve this answer










                                      answered Sep 7 at 11:37









                                      Sentinel

                                      1,012112




                                      1,012112











                                      • Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
                                        – user477343
                                        Sep 7 at 11:51







                                      • 2




                                        @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
                                        – Fabian Röling
                                        Sep 7 at 12:02










                                      • @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
                                        – user477343
                                        Sep 7 at 12:09







                                      • 3




                                        @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
                                        – Jaap Scherphuis
                                        Sep 7 at 12:55






                                      • 1




                                        Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
                                        – Sentinel
                                        Sep 7 at 14:44
















                                      • Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
                                        – user477343
                                        Sep 7 at 11:51







                                      • 2




                                        @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
                                        – Fabian Röling
                                        Sep 7 at 12:02










                                      • @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
                                        – user477343
                                        Sep 7 at 12:09







                                      • 3




                                        @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
                                        – Jaap Scherphuis
                                        Sep 7 at 12:55






                                      • 1




                                        Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
                                        – Sentinel
                                        Sep 7 at 14:44















                                      Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
                                      – user477343
                                      Sep 7 at 11:51





                                      Great answer, but unfortunately, this is a duplicate of @TheSimpliFire 's answer.
                                      – user477343
                                      Sep 7 at 11:51





                                      2




                                      2




                                      @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
                                      – Fabian Röling
                                      Sep 7 at 12:02




                                      @user477343 No, not quite, since this answer puts a line through the 0 instead of putting two 0s on top of each other. In this answer, only one 0 becomes an 8.
                                      – Fabian Röling
                                      Sep 7 at 12:02












                                      @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
                                      – user477343
                                      Sep 7 at 12:09





                                      @FabianRöling As I read it, it uses the minus symbol to be put over the first zero and make it look like an $8$. In my imagination, I assumed the zero is the bottom circle of $8$ since there is something over it, of which is another circle $largecirc$. I did not fully understand what this answer was talking about in saying to use a subtraction symbol, but just assumed it was just like TheSimpliFire's answer due to their similarity; and since that is a great answer, I thought this was great, too. If you understand this answer, may you please explain to me in other words if you can? :
                                      – user477343
                                      Sep 7 at 12:09





                                      3




                                      3




                                      @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
                                      – Jaap Scherphuis
                                      Sep 7 at 12:55




                                      @user477343 It uses the horizontal line of the minus sign to cut through the middle of the $0$. It is "over" the zero in the sense of overwritten.
                                      – Jaap Scherphuis
                                      Sep 7 at 12:55




                                      1




                                      1




                                      Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
                                      – Sentinel
                                      Sep 7 at 14:44




                                      Yeah. 'over' in the sense of "in front of" on a dimension between you and your monitor.
                                      – Sentinel
                                      Sep 7 at 14:44










                                      up vote
                                      3
                                      down vote













                                      Here is an answer that doesn't use the semi-factorial or any concatenation.




                                      $$0 + 0 - 0! / 0 = (-8)!$$




                                      The left side is $-1/0$ and the right side is $-infty$.




                                      Plugging the expression into Wolfram.






                                      share|improve this answer
















                                      • 4




                                        Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
                                        – dr jimbob
                                        Sep 8 at 18:11














                                      up vote
                                      3
                                      down vote













                                      Here is an answer that doesn't use the semi-factorial or any concatenation.




                                      $$0 + 0 - 0! / 0 = (-8)!$$




                                      The left side is $-1/0$ and the right side is $-infty$.




                                      Plugging the expression into Wolfram.






                                      share|improve this answer
















                                      • 4




                                        Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
                                        – dr jimbob
                                        Sep 8 at 18:11












                                      up vote
                                      3
                                      down vote










                                      up vote
                                      3
                                      down vote









                                      Here is an answer that doesn't use the semi-factorial or any concatenation.




                                      $$0 + 0 - 0! / 0 = (-8)!$$




                                      The left side is $-1/0$ and the right side is $-infty$.




                                      Plugging the expression into Wolfram.






                                      share|improve this answer












                                      Here is an answer that doesn't use the semi-factorial or any concatenation.




                                      $$0 + 0 - 0! / 0 = (-8)!$$




                                      The left side is $-1/0$ and the right side is $-infty$.




                                      Plugging the expression into Wolfram.







                                      share|improve this answer












                                      share|improve this answer



                                      share|improve this answer










                                      answered Sep 8 at 0:20









                                      user1717828

                                      1,474617




                                      1,474617







                                      • 4




                                        Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
                                        – dr jimbob
                                        Sep 8 at 18:11












                                      • 4




                                        Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
                                        – dr jimbob
                                        Sep 8 at 18:11







                                      4




                                      4




                                      Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
                                      – dr jimbob
                                      Sep 8 at 18:11




                                      Division by zero is undefined (the limit of 0!/x as x goes to 0 is plus or minus infinity) and so are negative integer factorials (they are not equivalent to negative infinity). Even if they both evaluated to +∞, you can prove nonsense assuming you can equate infinities and treat like a real number. E.g., |1/0| = +∞, adding 1 to positive infinity is still positive infinity, hence |1/0| + 1 = +∞, hence |1/0| = |1/0| +1 by transitivity of equality. Subtract |1/0| from both sides and prove 0 = 1.
                                      – dr jimbob
                                      Sep 8 at 18:11










                                      up vote
                                      2
                                      down vote













                                      Question limits the symbols, not the operations. So with the symbol + can make the operator ++.




                                      (++(++(++(++(++(++(++0000))))))) = 8







                                      share|improve this answer






















                                      • I think you'd need the prefix form if you actually wanted that to work.
                                        – LegionMammal978
                                        Sep 7 at 23:48






                                      • 1




                                        Doh. Of course you can't increment a literal in the first place.
                                        – David Browne - Microsoft
                                        Sep 7 at 23:55






                                      • 1




                                        but that symbol doesn't exist in mathematics
                                        – phuclv
                                        Sep 8 at 4:20






                                      • 2




                                        You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
                                        – NieDzejkob
                                        Sep 8 at 14:35














                                      up vote
                                      2
                                      down vote













                                      Question limits the symbols, not the operations. So with the symbol + can make the operator ++.




                                      (++(++(++(++(++(++(++0000))))))) = 8







                                      share|improve this answer






















                                      • I think you'd need the prefix form if you actually wanted that to work.
                                        – LegionMammal978
                                        Sep 7 at 23:48






                                      • 1




                                        Doh. Of course you can't increment a literal in the first place.
                                        – David Browne - Microsoft
                                        Sep 7 at 23:55






                                      • 1




                                        but that symbol doesn't exist in mathematics
                                        – phuclv
                                        Sep 8 at 4:20






                                      • 2




                                        You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
                                        – NieDzejkob
                                        Sep 8 at 14:35












                                      up vote
                                      2
                                      down vote










                                      up vote
                                      2
                                      down vote









                                      Question limits the symbols, not the operations. So with the symbol + can make the operator ++.




                                      (++(++(++(++(++(++(++0000))))))) = 8







                                      share|improve this answer














                                      Question limits the symbols, not the operations. So with the symbol + can make the operator ++.




                                      (++(++(++(++(++(++(++0000))))))) = 8








                                      share|improve this answer














                                      share|improve this answer



                                      share|improve this answer








                                      edited Sep 7 at 23:53

























                                      answered Sep 7 at 21:23









                                      David Browne - Microsoft

                                      1293




                                      1293











                                      • I think you'd need the prefix form if you actually wanted that to work.
                                        – LegionMammal978
                                        Sep 7 at 23:48






                                      • 1




                                        Doh. Of course you can't increment a literal in the first place.
                                        – David Browne - Microsoft
                                        Sep 7 at 23:55






                                      • 1




                                        but that symbol doesn't exist in mathematics
                                        – phuclv
                                        Sep 8 at 4:20






                                      • 2




                                        You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
                                        – NieDzejkob
                                        Sep 8 at 14:35
















                                      • I think you'd need the prefix form if you actually wanted that to work.
                                        – LegionMammal978
                                        Sep 7 at 23:48






                                      • 1




                                        Doh. Of course you can't increment a literal in the first place.
                                        – David Browne - Microsoft
                                        Sep 7 at 23:55






                                      • 1




                                        but that symbol doesn't exist in mathematics
                                        – phuclv
                                        Sep 8 at 4:20






                                      • 2




                                        You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
                                        – NieDzejkob
                                        Sep 8 at 14:35















                                      I think you'd need the prefix form if you actually wanted that to work.
                                      – LegionMammal978
                                      Sep 7 at 23:48




                                      I think you'd need the prefix form if you actually wanted that to work.
                                      – LegionMammal978
                                      Sep 7 at 23:48




                                      1




                                      1




                                      Doh. Of course you can't increment a literal in the first place.
                                      – David Browne - Microsoft
                                      Sep 7 at 23:55




                                      Doh. Of course you can't increment a literal in the first place.
                                      – David Browne - Microsoft
                                      Sep 7 at 23:55




                                      1




                                      1




                                      but that symbol doesn't exist in mathematics
                                      – phuclv
                                      Sep 8 at 4:20




                                      but that symbol doesn't exist in mathematics
                                      – phuclv
                                      Sep 8 at 4:20




                                      2




                                      2




                                      You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
                                      – NieDzejkob
                                      Sep 8 at 14:35




                                      You need to pass an l-value to the ++ and -- operators, and neither their result or a literal is one.
                                      – NieDzejkob
                                      Sep 8 at 14:35










                                      up vote
                                      2
                                      down vote














                                      concatenate(0!, 0) - concatenate(0! + 0!) = 8.




                                      Note that 0! = 1




                                      (0!, 0) = 10, and (0! + 0!) = 2, so 10 - 2 = 8







                                      share|improve this answer






















                                      • Unfortunately concatenate is not a valid operation.
                                        – boboquack
                                        Sep 11 at 1:37










                                      • Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
                                        – Alto
                                        Sep 11 at 1:47










                                      • Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
                                        – Alto
                                        Sep 11 at 1:48














                                      up vote
                                      2
                                      down vote














                                      concatenate(0!, 0) - concatenate(0! + 0!) = 8.




                                      Note that 0! = 1




                                      (0!, 0) = 10, and (0! + 0!) = 2, so 10 - 2 = 8







                                      share|improve this answer






















                                      • Unfortunately concatenate is not a valid operation.
                                        – boboquack
                                        Sep 11 at 1:37










                                      • Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
                                        – Alto
                                        Sep 11 at 1:47










                                      • Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
                                        – Alto
                                        Sep 11 at 1:48












                                      up vote
                                      2
                                      down vote










                                      up vote
                                      2
                                      down vote










                                      concatenate(0!, 0) - concatenate(0! + 0!) = 8.




                                      Note that 0! = 1




                                      (0!, 0) = 10, and (0! + 0!) = 2, so 10 - 2 = 8







                                      share|improve this answer















                                      concatenate(0!, 0) - concatenate(0! + 0!) = 8.




                                      Note that 0! = 1




                                      (0!, 0) = 10, and (0! + 0!) = 2, so 10 - 2 = 8








                                      share|improve this answer














                                      share|improve this answer



                                      share|improve this answer








                                      edited Sep 11 at 1:59









                                      Alto

                                      908116




                                      908116










                                      answered Sep 11 at 0:57









                                      Nick

                                      191




                                      191











                                      • Unfortunately concatenate is not a valid operation.
                                        – boboquack
                                        Sep 11 at 1:37










                                      • Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
                                        – Alto
                                        Sep 11 at 1:47










                                      • Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
                                        – Alto
                                        Sep 11 at 1:48
















                                      • Unfortunately concatenate is not a valid operation.
                                        – boboquack
                                        Sep 11 at 1:37










                                      • Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
                                        – Alto
                                        Sep 11 at 1:47










                                      • Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
                                        – Alto
                                        Sep 11 at 1:48















                                      Unfortunately concatenate is not a valid operation.
                                      – boboquack
                                      Sep 11 at 1:37




                                      Unfortunately concatenate is not a valid operation.
                                      – boboquack
                                      Sep 11 at 1:37












                                      Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
                                      – Alto
                                      Sep 11 at 1:47




                                      Congrats, concatenation is allowed now! Good answer, but people beat you to it. Welcome to Puzzling.SE! Here's a bonus puzzle: What's the word? Hilarious - extremely amusing
                                      – Alto
                                      Sep 11 at 1:47












                                      Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
                                      – Alto
                                      Sep 11 at 1:48




                                      Also, concatenation is combination. Basically, (2, 4) = 24, you get it.
                                      – Alto
                                      Sep 11 at 1:48










                                      up vote
                                      2
                                      down vote














                                      Add a - above the equals to get $0000 equiv 8$, which is true assuming we are working in the ring $mathbbZ/mathbb2Z$. (Note I'm trying to avoid writing $[0] = [8]$...)







                                      share|improve this answer


























                                        up vote
                                        2
                                        down vote














                                        Add a - above the equals to get $0000 equiv 8$, which is true assuming we are working in the ring $mathbbZ/mathbb2Z$. (Note I'm trying to avoid writing $[0] = [8]$...)







                                        share|improve this answer
























                                          up vote
                                          2
                                          down vote










                                          up vote
                                          2
                                          down vote










                                          Add a - above the equals to get $0000 equiv 8$, which is true assuming we are working in the ring $mathbbZ/mathbb2Z$. (Note I'm trying to avoid writing $[0] = [8]$...)







                                          share|improve this answer















                                          Add a - above the equals to get $0000 equiv 8$, which is true assuming we are working in the ring $mathbbZ/mathbb2Z$. (Note I'm trying to avoid writing $[0] = [8]$...)








                                          share|improve this answer














                                          share|improve this answer



                                          share|improve this answer








                                          edited Sep 14 at 2:45









                                          a stone arachnid

                                          1355




                                          1355










                                          answered Sep 11 at 15:52









                                          Gus314

                                          211




                                          211




















                                              up vote
                                              1
                                              down vote













                                              This could work too:




                                              (0!+0+0)/0 = ∞




                                              Explanation




                                              (0!+0+0)/0 = 1/0 which is infinity (8 but put horizontally)







                                              share|improve this answer
























                                                up vote
                                                1
                                                down vote













                                                This could work too:




                                                (0!+0+0)/0 = ∞




                                                Explanation




                                                (0!+0+0)/0 = 1/0 which is infinity (8 but put horizontally)







                                                share|improve this answer






















                                                  up vote
                                                  1
                                                  down vote










                                                  up vote
                                                  1
                                                  down vote









                                                  This could work too:




                                                  (0!+0+0)/0 = ∞




                                                  Explanation




                                                  (0!+0+0)/0 = 1/0 which is infinity (8 but put horizontally)







                                                  share|improve this answer












                                                  This could work too:




                                                  (0!+0+0)/0 = ∞




                                                  Explanation




                                                  (0!+0+0)/0 = 1/0 which is infinity (8 but put horizontally)








                                                  share|improve this answer












                                                  share|improve this answer



                                                  share|improve this answer










                                                  answered Sep 13 at 9:10









                                                  Michal B.

                                                  1314




                                                  1314




















                                                      up vote
                                                      0
                                                      down vote














                                                      $ ((0! + 0!)$)*(0! + 0!) = 2^2*2 = 8 $.




                                                      Further explanation:




                                                      The $$$ operation denotes the superfactorial defined as : $ n$ = (n!) uparrow uparrow (n!)$.







                                                      share|improve this answer


















                                                      • 3




                                                        Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
                                                        – Sensoray
                                                        Sep 7 at 15:26














                                                      up vote
                                                      0
                                                      down vote














                                                      $ ((0! + 0!)$)*(0! + 0!) = 2^2*2 = 8 $.




                                                      Further explanation:




                                                      The $$$ operation denotes the superfactorial defined as : $ n$ = (n!) uparrow uparrow (n!)$.







                                                      share|improve this answer


















                                                      • 3




                                                        Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
                                                        – Sensoray
                                                        Sep 7 at 15:26












                                                      up vote
                                                      0
                                                      down vote










                                                      up vote
                                                      0
                                                      down vote










                                                      $ ((0! + 0!)$)*(0! + 0!) = 2^2*2 = 8 $.




                                                      Further explanation:




                                                      The $$$ operation denotes the superfactorial defined as : $ n$ = (n!) uparrow uparrow (n!)$.







                                                      share|improve this answer















                                                      $ ((0! + 0!)$)*(0! + 0!) = 2^2*2 = 8 $.




                                                      Further explanation:




                                                      The $$$ operation denotes the superfactorial defined as : $ n$ = (n!) uparrow uparrow (n!)$.








                                                      share|improve this answer














                                                      share|improve this answer



                                                      share|improve this answer








                                                      edited Sep 7 at 14:41

























                                                      answered Sep 7 at 14:28









                                                      Ria

                                                      354111




                                                      354111







                                                      • 3




                                                        Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
                                                        – Sensoray
                                                        Sep 7 at 15:26












                                                      • 3




                                                        Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
                                                        – Sensoray
                                                        Sep 7 at 15:26







                                                      3




                                                      3




                                                      Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
                                                      – Sensoray
                                                      Sep 7 at 15:26




                                                      Good idea, but make sure to read the question fully. It gives you a list of what operations can be used and $ is not one of them.
                                                      – Sensoray
                                                      Sep 7 at 15:26










                                                      up vote
                                                      0
                                                      down vote













                                                      If you turn the problem around




                                                      enter image description here







                                                      share|improve this answer




















                                                      • Similar to @rrauenza's answer
                                                        – TheSimpliFire
                                                        Sep 8 at 8:11










                                                      • Yes. A different way to express the same idea.
                                                        – Florian F
                                                        Sep 8 at 9:13














                                                      up vote
                                                      0
                                                      down vote













                                                      If you turn the problem around




                                                      enter image description here







                                                      share|improve this answer




















                                                      • Similar to @rrauenza's answer
                                                        – TheSimpliFire
                                                        Sep 8 at 8:11










                                                      • Yes. A different way to express the same idea.
                                                        – Florian F
                                                        Sep 8 at 9:13












                                                      up vote
                                                      0
                                                      down vote










                                                      up vote
                                                      0
                                                      down vote









                                                      If you turn the problem around




                                                      enter image description here







                                                      share|improve this answer












                                                      If you turn the problem around




                                                      enter image description here








                                                      share|improve this answer












                                                      share|improve this answer



                                                      share|improve this answer










                                                      answered Sep 8 at 8:09









                                                      Florian F

                                                      8,94612260




                                                      8,94612260











                                                      • Similar to @rrauenza's answer
                                                        – TheSimpliFire
                                                        Sep 8 at 8:11










                                                      • Yes. A different way to express the same idea.
                                                        – Florian F
                                                        Sep 8 at 9:13
















                                                      • Similar to @rrauenza's answer
                                                        – TheSimpliFire
                                                        Sep 8 at 8:11










                                                      • Yes. A different way to express the same idea.
                                                        – Florian F
                                                        Sep 8 at 9:13















                                                      Similar to @rrauenza's answer
                                                      – TheSimpliFire
                                                      Sep 8 at 8:11




                                                      Similar to @rrauenza's answer
                                                      – TheSimpliFire
                                                      Sep 8 at 8:11












                                                      Yes. A different way to express the same idea.
                                                      – Florian F
                                                      Sep 8 at 9:13




                                                      Yes. A different way to express the same idea.
                                                      – Florian F
                                                      Sep 8 at 9:13










                                                      up vote
                                                      0
                                                      down vote














                                                      As per the list of allowed symbols we are clearly allowed to use "$,$" and "$.$"

                                                      This is doubly evident as otherwise how would we use the $mathbbconcatenation$ function without a comma to separate the arguments?




                                                      So the solution is:




                                                      $0! - mathbbconcatenation(., 0 + 0! + 0!!) = .8$

                                                      $1 - mathbbconcatenation(., 0 + 1 + 1) = .8$

                                                      $1 - mathbbconcatenation(., 2) = .8$

                                                      $1 - .2 = .8$







                                                      share|improve this answer




















                                                      • You may simplify 0!! as 0!.
                                                        – Cœur
                                                        Sep 11 at 15:28










                                                      • I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
                                                        – SamYonnou
                                                        Sep 11 at 16:58














                                                      up vote
                                                      0
                                                      down vote














                                                      As per the list of allowed symbols we are clearly allowed to use "$,$" and "$.$"

                                                      This is doubly evident as otherwise how would we use the $mathbbconcatenation$ function without a comma to separate the arguments?




                                                      So the solution is:




                                                      $0! - mathbbconcatenation(., 0 + 0! + 0!!) = .8$

                                                      $1 - mathbbconcatenation(., 0 + 1 + 1) = .8$

                                                      $1 - mathbbconcatenation(., 2) = .8$

                                                      $1 - .2 = .8$







                                                      share|improve this answer




















                                                      • You may simplify 0!! as 0!.
                                                        – Cœur
                                                        Sep 11 at 15:28










                                                      • I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
                                                        – SamYonnou
                                                        Sep 11 at 16:58












                                                      up vote
                                                      0
                                                      down vote










                                                      up vote
                                                      0
                                                      down vote










                                                      As per the list of allowed symbols we are clearly allowed to use "$,$" and "$.$"

                                                      This is doubly evident as otherwise how would we use the $mathbbconcatenation$ function without a comma to separate the arguments?




                                                      So the solution is:




                                                      $0! - mathbbconcatenation(., 0 + 0! + 0!!) = .8$

                                                      $1 - mathbbconcatenation(., 0 + 1 + 1) = .8$

                                                      $1 - mathbbconcatenation(., 2) = .8$

                                                      $1 - .2 = .8$







                                                      share|improve this answer













                                                      As per the list of allowed symbols we are clearly allowed to use "$,$" and "$.$"

                                                      This is doubly evident as otherwise how would we use the $mathbbconcatenation$ function without a comma to separate the arguments?




                                                      So the solution is:




                                                      $0! - mathbbconcatenation(., 0 + 0! + 0!!) = .8$

                                                      $1 - mathbbconcatenation(., 0 + 1 + 1) = .8$

                                                      $1 - mathbbconcatenation(., 2) = .8$

                                                      $1 - .2 = .8$








                                                      share|improve this answer












                                                      share|improve this answer



                                                      share|improve this answer










                                                      answered Sep 10 at 16:55









                                                      SamYonnou

                                                      22115




                                                      22115











                                                      • You may simplify 0!! as 0!.
                                                        – Cœur
                                                        Sep 11 at 15:28










                                                      • I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
                                                        – SamYonnou
                                                        Sep 11 at 16:58
















                                                      • You may simplify 0!! as 0!.
                                                        – Cœur
                                                        Sep 11 at 15:28










                                                      • I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
                                                        – SamYonnou
                                                        Sep 11 at 16:58















                                                      You may simplify 0!! as 0!.
                                                      – Cœur
                                                      Sep 11 at 15:28




                                                      You may simplify 0!! as 0!.
                                                      – Cœur
                                                      Sep 11 at 15:28












                                                      I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
                                                      – SamYonnou
                                                      Sep 11 at 16:58




                                                      I felt like $0+0!+0!!$ looked more elegant/purposeful as if it was part of a sequence like $a(n, m) = a(n-1,m)!; a(0,m)=m$
                                                      – SamYonnou
                                                      Sep 11 at 16:58










                                                      up vote
                                                      -1
                                                      down vote














                                                      $00^00 = 0^0$ which is indeterminate. In some sense, an indeterminate form can be equal to any value, since in Calculus, a function that approaches "$0^0$" can approach any real value, including $8$. So in that sense, $0^0 = 8$.


                                                      If you don't like concatenating two zeroes as "$00$", then $0^0 + 0 + 0$ also works.







                                                      share|improve this answer


















                                                      • 7




                                                        There are no widely accepted definitions under which your equation is considered to be true.
                                                        – Tanner Swett
                                                        Sep 7 at 17:34










                                                      • @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
                                                        – RothX
                                                        Sep 10 at 13:23











                                                      • Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
                                                        – Tanner Swett
                                                        Sep 10 at 13:59










                                                      • @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
                                                        – RothX
                                                        Sep 11 at 1:58














                                                      up vote
                                                      -1
                                                      down vote














                                                      $00^00 = 0^0$ which is indeterminate. In some sense, an indeterminate form can be equal to any value, since in Calculus, a function that approaches "$0^0$" can approach any real value, including $8$. So in that sense, $0^0 = 8$.


                                                      If you don't like concatenating two zeroes as "$00$", then $0^0 + 0 + 0$ also works.







                                                      share|improve this answer


















                                                      • 7




                                                        There are no widely accepted definitions under which your equation is considered to be true.
                                                        – Tanner Swett
                                                        Sep 7 at 17:34










                                                      • @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
                                                        – RothX
                                                        Sep 10 at 13:23











                                                      • Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
                                                        – Tanner Swett
                                                        Sep 10 at 13:59










                                                      • @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
                                                        – RothX
                                                        Sep 11 at 1:58












                                                      up vote
                                                      -1
                                                      down vote










                                                      up vote
                                                      -1
                                                      down vote










                                                      $00^00 = 0^0$ which is indeterminate. In some sense, an indeterminate form can be equal to any value, since in Calculus, a function that approaches "$0^0$" can approach any real value, including $8$. So in that sense, $0^0 = 8$.


                                                      If you don't like concatenating two zeroes as "$00$", then $0^0 + 0 + 0$ also works.







                                                      share|improve this answer















                                                      $00^00 = 0^0$ which is indeterminate. In some sense, an indeterminate form can be equal to any value, since in Calculus, a function that approaches "$0^0$" can approach any real value, including $8$. So in that sense, $0^0 = 8$.


                                                      If you don't like concatenating two zeroes as "$00$", then $0^0 + 0 + 0$ also works.








                                                      share|improve this answer














                                                      share|improve this answer



                                                      share|improve this answer








                                                      edited Sep 7 at 13:30

























                                                      answered Sep 7 at 13:22









                                                      RothX

                                                      1173




                                                      1173







                                                      • 7




                                                        There are no widely accepted definitions under which your equation is considered to be true.
                                                        – Tanner Swett
                                                        Sep 7 at 17:34










                                                      • @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
                                                        – RothX
                                                        Sep 10 at 13:23











                                                      • Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
                                                        – Tanner Swett
                                                        Sep 10 at 13:59










                                                      • @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
                                                        – RothX
                                                        Sep 11 at 1:58












                                                      • 7




                                                        There are no widely accepted definitions under which your equation is considered to be true.
                                                        – Tanner Swett
                                                        Sep 7 at 17:34










                                                      • @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
                                                        – RothX
                                                        Sep 10 at 13:23











                                                      • Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
                                                        – Tanner Swett
                                                        Sep 10 at 13:59










                                                      • @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
                                                        – RothX
                                                        Sep 11 at 1:58







                                                      7




                                                      7




                                                      There are no widely accepted definitions under which your equation is considered to be true.
                                                      – Tanner Swett
                                                      Sep 7 at 17:34




                                                      There are no widely accepted definitions under which your equation is considered to be true.
                                                      – Tanner Swett
                                                      Sep 7 at 17:34












                                                      @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
                                                      – RothX
                                                      Sep 10 at 13:23





                                                      @TannerSwett Didn't think it was that unreasonable. My thinking is you can construct a function $f(x)^g(x)$ where $f$ and $g$ both limit to zero at some point $c$ such that $f(x)^g(x)$ limits to any real number at $c$, including $8$. Admittedly, writing $0^0 = 8$ is basically mathematically false. It is indeterminate for the reason I stated above. But this is Puzzling SE, not Mathematics SE, so I figured it was ok to think outside the box and not be formal with math.
                                                      – RothX
                                                      Sep 10 at 13:23













                                                      Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
                                                      – Tanner Swett
                                                      Sep 10 at 13:59




                                                      Yeah, I dunno if I'd call it "that unreasonable". But if I saw a student say that the equation $0^0 = 8$ is true, I'd think that they probably misunderstand what an indeterminate form means. If I saw a math professor say the same thing, I'd ask them if they could please be a little more rigorous.
                                                      – Tanner Swett
                                                      Sep 10 at 13:59












                                                      @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
                                                      – RothX
                                                      Sep 11 at 1:58




                                                      @TannerSwett Yeah, I completely agree. I'd never write $0^0 = 8$ in a mathematical setting, but since this is a puzzle, not a math problem, I thought maybe I could stretch a bit.
                                                      – RothX
                                                      Sep 11 at 1:58










                                                      up vote
                                                      -1
                                                      down vote













                                                      Factorial of Zero equals to 1. And 4!!=8.
                                                      Then you can put plus and power to end up the story.
                                                      ((0!+0!)^(0!+0!))!!






                                                      share|improve this answer


















                                                      • 4




                                                        this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
                                                        – JonMark Perry
                                                        Sep 8 at 7:55











                                                      • Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
                                                        – F1Krazy
                                                        Sep 8 at 8:55














                                                      up vote
                                                      -1
                                                      down vote













                                                      Factorial of Zero equals to 1. And 4!!=8.
                                                      Then you can put plus and power to end up the story.
                                                      ((0!+0!)^(0!+0!))!!






                                                      share|improve this answer


















                                                      • 4




                                                        this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
                                                        – JonMark Perry
                                                        Sep 8 at 7:55











                                                      • Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
                                                        – F1Krazy
                                                        Sep 8 at 8:55












                                                      up vote
                                                      -1
                                                      down vote










                                                      up vote
                                                      -1
                                                      down vote









                                                      Factorial of Zero equals to 1. And 4!!=8.
                                                      Then you can put plus and power to end up the story.
                                                      ((0!+0!)^(0!+0!))!!






                                                      share|improve this answer














                                                      Factorial of Zero equals to 1. And 4!!=8.
                                                      Then you can put plus and power to end up the story.
                                                      ((0!+0!)^(0!+0!))!!







                                                      share|improve this answer














                                                      share|improve this answer



                                                      share|improve this answer








                                                      edited Sep 8 at 10:53

























                                                      answered Sep 8 at 7:48









                                                      Salman Khan Majlish

                                                      11




                                                      11







                                                      • 4




                                                        this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
                                                        – JonMark Perry
                                                        Sep 8 at 7:55











                                                      • Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
                                                        – F1Krazy
                                                        Sep 8 at 8:55












                                                      • 4




                                                        this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
                                                        – JonMark Perry
                                                        Sep 8 at 7:55











                                                      • Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
                                                        – F1Krazy
                                                        Sep 8 at 8:55







                                                      4




                                                      4




                                                      this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
                                                      – JonMark Perry
                                                      Sep 8 at 7:55





                                                      this is almost un_defined's answer, given 17hours ago, except for you haven't added the double factorial to make the sum correct - yours gives 2^2 which is 4
                                                      – JonMark Perry
                                                      Sep 8 at 7:55













                                                      Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
                                                      – F1Krazy
                                                      Sep 8 at 8:55




                                                      Welcome to Puzzling.SE! As JonMark Perry has noted, please check that your answer hasn't already been given (and that it's correct) before posting it. You should also hide answers inside spoiler tags, in case anyone wants to have a go at the puzzle themselves without seeing the answers first. Please take the tour and visit the help center to learn more about the site.
                                                      – F1Krazy
                                                      Sep 8 at 8:55










                                                      up vote
                                                      -1
                                                      down vote













                                                      Similar to @Vaelus




                                                      $0+0+0+0 leq 8$




                                                      Explanation




                                                      You can get the $leq$ by adding a $-$ inclined on top of the $=$







                                                      share|improve this answer
























                                                        up vote
                                                        -1
                                                        down vote













                                                        Similar to @Vaelus




                                                        $0+0+0+0 leq 8$




                                                        Explanation




                                                        You can get the $leq$ by adding a $-$ inclined on top of the $=$







                                                        share|improve this answer






















                                                          up vote
                                                          -1
                                                          down vote










                                                          up vote
                                                          -1
                                                          down vote









                                                          Similar to @Vaelus




                                                          $0+0+0+0 leq 8$




                                                          Explanation




                                                          You can get the $leq$ by adding a $-$ inclined on top of the $=$







                                                          share|improve this answer












                                                          Similar to @Vaelus




                                                          $0+0+0+0 leq 8$




                                                          Explanation




                                                          You can get the $leq$ by adding a $-$ inclined on top of the $=$








                                                          share|improve this answer












                                                          share|improve this answer



                                                          share|improve this answer










                                                          answered Sep 8 at 19:44









                                                          villasv

                                                          1387




                                                          1387



























                                                               

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