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 :)

  • chuckleslord@lemmy.world
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    1 year ago

    It’s covered in the blog, but this is likely due to a bias towards Strong Juxtaposition rules for parentheses rather than Weak. It’s common for those who learned math into advanced algebra/ beginning Calc and beyond, since that’s the usual method for higher math education. But it isn’t “correct”, it’s one of two standard ways of doing it. The ambiguity in the question is intentional and pervasive.

    • But it isn’t “correct”

      It is correct - it’s The Distributive Law.

      it’s one of two standard ways of doing it.

      There’s only 1 way - the “other way” was made up by people who don’t remember The Distributive Law and/or Terms (more likely both), and very much goes against the standards.

      The ambiguity in the question is

      …zero.

    • Portosian@sh.itjust.works
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      1 year ago

      My argument is specifically that using no separation shows intent for which way to interpret and should not default to weak juxtaposition.

      Choosing not to use (6/2)(1+2) implies to me to use the only other interpretation.

      There’s also the difference between 6/2(1+2) and 6/2*(1+2). I think the post has a point for the latter, but not the former.

      • chuckleslord@lemmy.world
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        1 year ago

        I don’t know what you want, man. The blog’s goal is to describe the problem and why it comes about and your response is “Following my logic, there is no confusion!” when there clearly is confusion in the wider world here. The blog does a good job of narrowing down why there’s confusion, you’re response doesn’t add anything or refute anything. It’s just… you bragging? I’m not certain what your point is.

        • your response is “Following my logic, there is no confusion!”

          That’s because the actual rules of Maths have all been followed, including The Distributive Law and Terms.

          there clearly is confusion in the wider world here

          Amongst people who don’t remember The Distributive Law and Terms.

          The blog does a good job of narrowing down why there’s confusion

          The blog ignores The Distributive Law and Terms. Notice the complete lack of Maths textbook references in it?

      • atomicorange@lemmy.world
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        1 year ago

        I originally had the same reasoning but came to the opposite conclusion. Multiplication and division have the same precedence, so I read the operations from left to right unless noted otherwise with parentheses. Thus:

        6/2=3

        3(1+2)=9

        For me to read the whole of 2(1+2) as the denominator in a fraction I would expect it to be isolated in parentheses: 6/(2(1+2)).

        Reading the blog post, I understand the ambiguity now, but i’m still fascinated that we had the same criticism (no parentheses implies intent) but had opposite conclusions.