https://zeta.one/viral-math/

I wrote a (very long) blog post about those viral math problems and am looking for feedback, especially from people who are not convinced that the problem is ambiguous.

It’s about a 30min read so thank you in advance if you really take the time to read it, but I think it’s worth it if you joined such discussions in the past, but I’m probably biased because I wrote it :)

  • @Prunebutt@feddit.de
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    881 year ago

    If you are so sure that you are right and already “know it all”, why bother and even read this? There is no comment section to argue.

    I beg to differ. You utter fool! You created a comment section yourself on lemmy and you are clearly wrong about everything!

    You take the mean of 1 and 9 which is 4.5!

    /j

    • @wischi@programming.devOP
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      341 year ago

      🤣 I wasn’t even sure if I should post it on lemmy. I mainly wrote it so I can post it under other peoples posts that actually are intended to artificially create drama to hopefully show enough people what the actual problems are with those puzzles.

      But I probably am a fool and this is not going anywhere because most people won’t read a 30min article about those math problems :-)

      • @wischi@programming.devOP
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        51 year ago

        @Prunebutt meant 4.5! and not 4.5. Because it’s not an integer we have to use the gamma function, the extension of the factorial function to get the actual mean between 1 and 9 => 4.5! = 52.3428 which looks about right 🤣

            • pitninja
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              41 year ago

              I think you got hit hard by Poe’s Law here. Except it’s more like people couldn’t tell if you were jokingly or genuinely getting your math wrong… Even after you explained you were joking lol

                • Redjard
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                  11 year ago

                  If one doesn’t realize you’re op, the entire thing can be interpreted very differently.
                  Then “Not sure if sarcastic and woosh, or adding to the joke ಠ_ಠ” could be interpreted as something like “I’m not sure if you are adding to the joke and I’m not understanding it”.

  • @Kichae@lemmy.ca
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    1 year ago

    Ackshually, the answer is 4

    6÷2*(1+2)

    6÷(1+2)*2

    6÷(3)*2

    2*2

    4

    You’re welcome

  • Th4tGuyII
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    1 year ago

    The answer realistically is determined by where you place implicit multiplication (or “multiplication by juxtaposition”) in the order of operations.

    Some place it above explicit multiplication and division, meaning it gets done before the division giving you an answer of 1

    But if you place it as equal to it’s explicit counterparts, then you’d sweep left to right giving you an answer of 9

    Since those are both valid interpretations of the order of operations dependent on what field you’re in, you’re always going to end up with disagreements on questions like these…

    But in reality nobody would write an equation like this, and even if they did, there would usually be some kind of context (I.e. units) to guide you as to what the answer should be.

    Edit: Just skimmed that article, and it looks like I did remember the last explanation I heard about these correctly. Yay me!

    • @wischi@programming.devOP
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      261 year ago

      Exactly. With the blog post I try to reach people who already heared that some people say it’s ambiguous but either down understand how, or don’t believe it. I’m not sure if that will work out because people who “already know the only correct answer” probably won’t read a 30min blog post.

      • Th4tGuyII
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        131 year ago

        Unfortunately these types of viral problems are designed the attract people who think they “know it all”, so convincing them that their chosen answer isn’t as right as they think it is will always be an uphill challenge

    • @BCsven@lemmy.ca
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      21 year ago

      yeah, our math profs taught if the 2( is to be separated from that bracket for the implied multiplication then you do that math first, because the 2(1+2) is the same as (1+2)+(1+2) and not related to the first 6.

      • Th4tGuyII
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        1 year ago

        So you were taught strong juxtaposition then, where the implicit multiplication takes priority?

        • @BCsven@lemmy.ca
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          21 year ago

          if it was 6÷2x(2+1) they suggested do division and mult from left to right, but 6÷2(2+1) implied a relationship between the number outside the parenthesis and inside them, and as soon as you broke those () you had to do the multiplication immediately that is connected to them. Like some models of calculatora do. wasn’t till a few yeara ago that I heard people were doing it differently.

          • if it was 6÷2x(2+1) they suggested do division and mult from left to right, but 6÷2(2+1)

            Correct! Terms are separated by operators and joined by grouping symbols, so 6÷2x(2+1) is 3 terms - 6, 2, and (2+1) - whereas 6÷2(2+1) is 2 terms - 6 and 2(2+1), and the latter term has a precedence of “brackets”, NOT “multiplication”. Multiplication refers literally to multiplication signs, which are only present in your first example (hence evaluated with a different order than your second example).

            Also noted that the OP has ignored your comment, seeing as how you pointed out the unambiguous way to do it.

    • implicit multiplication

      There’s no such thing as “implicit multiplication”

      Some place it above explicit multiplication and division,

      Which is correct, seeing as how we’re solving brackets, and brackets always come first.

      But if you place it as equal to it’s explicit counterparts, then you’d sweep left to right giving you an answer of 9

      Which is wrong.

      Since those are both valid interpretations of the order of operations

      No, they’re not. Treating brackets as, you know, brackets, is the only valid interpretation. “Multiplication” refers literally to multiplication signs, of which there are none in this problem.

      But in reality nobody would write an equation like this

      Yes they would. a(b+c) is the standard way to write a factorised term.

  • @youngalfred@lemm.ee
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    471 year ago

    Typo in article:

    If you are however willing to except the possibility that you are wrong.

    Except should be ‘accept’.

    Not trying to be annoying, but I know people will often find that as a reason to disregard academic arguments.

  • I tried explaining this to people on facebook in 2010 or so.

    “You must be fun at parties!”

    Bitch, i dont want to attend your lame ass party where people think they know how math works.

  • @Pulptastic@midwest.social
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    1 year ago

    I disagree. Without explicit direction on OOO we have to follow the operators in order.

    The parentheses go first. 1+2=3

    Then we have 6 ÷2 ×3

    Without parentheses around (2×3) we can’t do that first. So OOO would be left to right. 9.

    In other words, as an engineer with half a PhD, I don’t buy strong juxtaposition. That sounds more like laziness than math.

  • @vithigar@lemmy.ca
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    281 year ago

    What’s especially wild to me is that even the position of “it’s ambiguous” gets almost as much pushback as trying to argue that one of them is universally correct.

    Last time this came up it was my position that it was ambiguous and needed clarification and had someone accuse me of taking a prescriptive stance and imposing rules contrary to how things were actually being done. How asking a person what they mean or seeking clarification could possibly be prescriptive is beyond me.

    Bonus points, the guy telling me I was being prescriptive was arguing vehemently that implicit multiplication having precedence was correct and to do otherwise was wrong, full stop.

    • @wischi@programming.devOP
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      1 year ago

      👍 That was actually one of the reasons why I wrote this blog post. I wanted to compile a list of points that show as clear as humanity possible that there is no consensus here, even amongst experts.

      That probably won’t convince everybody but if that won’t probably nothing will.

      • I wanted to compile a list of points that show as clear as humanity possible that there is no consensus here, even amongst experts

        And I wrote a bunch of fact checks pointing out there is consensus amongst the actual experts - high school Maths teachers and textbook authors, the 2 groups who you completely ignored in your blog post.

    • Ook the Librarian
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      41 year ago

      When I went to college, I was given a reverse Polish notation calculator. I think there is some (albeit small) advantage of becoming fluent in both PEMDAS and RPN to see the arbitrariness. This kind of arguement is like trying to argue linguistics in a single language.

      Btw, I’m not claiming that RPN has any bearing on the meme at hand. Just that there are different standards.

      This comment is left by the HP50g crew.

        • Ook the Librarian
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          1 year ago

          Ambiguity is fine. It would tedious to the point of distraction to enforce writing math without ambiguity. You make note of conventions and you are meant to realize that is just a convention. I’m amazed at the people who are planting their feet to fight for something that what they were taught in third grade as if the world stopped there.

          You’re right though. We should definitely teach different conventions. But then what would facebook do for engagement?

    • @Socsa@sh.itjust.works
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      21 year ago

      Without any additional parentheses, the division sign is assumed to separate numerators and denominators within a complete expression, in which case you would reduce each separately. It’s very, very marginally ambiguous at best.

    • What’s especially wild to me is that even the position of “it’s ambiguous” gets almost as much pushback as trying to argue that one of them is universally correct.

      That’s because following the rules of Maths is universally correct.

      arguing vehemently that implicit multiplication having precedence was correct and to do otherwise was wrong, full stop

      He was using the wrong words, but he was correct - the actual rules are The Distributive Law and Terms (“implicit multiplication” is a rule made up by those who have forgotten these 2 rules).

  • TimeSquirrel
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    1 year ago

    My TI-84 Plus is my holy oracle, I will go with whatever it says.

    And then get distracted and play some Doom.

  • @jdaxe@infosec.pub
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    241 year ago

    It’s hilarious seeing all the genius commenters who didn’t read the linked article and are repeating all the exact answers and arguments that the article rebuts :)

    • @RickyRigatoni@lemmy.ml
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      91 year ago

      I’m still not used to having combined image and text posts so I usually don’t notice the text portion if it isn’t a big ol’ wall and I hope I’m not the only one.

    • TheLastHero [none/use name]
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      81 year ago

      you are so sure that you are right and already “know it all”, why bother and even read this? There is no comment section to argue.

      he made a mistake posting this to a comment section, now he must pay the price

    • @wischi@programming.devOP
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      71 year ago

      ❤️ True, but I think one of the biggest problems is that it’s pretty long and because you can’t really sense how good/bad/convining the text is it’s always a gamble for everybody if it’s worth reading something for 30min just to find out that the content is garbage.

      I hope I did a decent job in explaining the issue(s) but I’m definitely not mad if someone decides that they are not going to read the post and still comment about it.

  • Just write it better.

    6/(2(1+2))

    Or

    (6/2)(1+2)

    That’s how it works in the real world when you’re using real numbers to calculate actual things anyways.

  • @Perfide@reddthat.com
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    1 year ago

    You lost me on the section when you started going into different calculators, but I read the rest of the post. Well written even if I ultimately disagree!

    The reason imo there is ambiguity with these math problems is bad/outdated teaching. The way I was taught pemdas, you always do the left-most operations first, while otherwise still following the ordering.

    Doing this for 6÷2(1+2), there is no ambiguity that the answer is 9. You do your parentheses first as always, 6÷2(3), and then since division and multiplication are equal in ordering weight, you do the division first because it’s the left most operation, leaving us 3(3), which is of course 9.

    If someone wrote this equation with the intention that the answer is 1, they wrote the equation wrong, simple as that.