• SkyeStarfall@lemmy.blahaj.zone
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    2 months ago

    That’s a very simplistic view of maths. It’s convention https://en.wikipedia.org/wiki/Order_of_operations

    Just because a definition of an operator contains another operator, does not require that operator to take precedence. As you pointed out, 2+3*4 could just as well be calculated to 5*4 and thus 20. There’s no mathematical contradiction there. Nothing broke. You just get a different answer. This is all perfectly in line with how maths work.

    You can think of operators as functions, in that case, you could rewrite 2+3*4 as add(2, mult(3, 4)), for typical convention. But it could just as well be mult(add(2, 3), 4), where addition takes precedence. Or, similarly, for 2*3+4, as add(mult(2, 3), 4) for typical convention, or mult(2, add(3, 4)), where addition takes precedence. And I hope you see how, in here, everything seems to work just fine, it just depends on how you rearrange things. This sort of functional breakdown of operators is much closer to mathematical reality, and our operators is just convention, to make it easier to read.

    Something in between would be requiring parentheses around every operator, to enforce order. Such as (2+(3*4)) or ((2+3)*4)

    • That’s a very simplistic view of maths

      The Distributive Law and Arithmetic is very simple.

      It’s convention

      Nope, a literal Law. See screenshot

      https://en.wikipedia.org/wiki/Order_of_operations

      Isn’t a Maths textbook, and has many mistakes in it

      Just because a definition of an operator contains another operator, does not require that operator to take precedence

      Yes it does 😂

      2+3x4=2+3+3+3+3=14 by definition of Multiplication

      2+3x4=5x4=20 Oops! WRONG ANSWER 😂

      As you pointed out, 2+34 could just as well be calculated to 54 and thus 20

      No, I pointed out that it can’t be calculated like that, you get a wrong answer, and you get a wrong answer because 3x4=3+3+3+3 by definition

      There’s no mathematical contradiction there

      Just a wrong answer and a right one. If I have 1 2 litre bottle of milk, and 4 3 litre bottles of milk, even young kids know how to count up how many litres I have. Go ahead and ask them what the correct answer is 🙄

      Nothing broke

      You got a wrong answer when you broke the rules of Maths. Spoiler alert: I don’t have 20 litres of milk

      You just get a different answer

      A provably wrong answer 😂

      This is all perfectly in line with how maths work

      2+3x4=20 is not in line with how Maths works. 2+3+3+3+3 does not equal 20 😂

      add(2, mult(3, 4)), for typical

      rule

      But it could just as well be mult(add(2, 3), 4), where addition takes precedence

      And it gives you a wrong answer 🙄 I still don’t have 20 litres of milk

      And I hope you see how, in here, everything seems to work just fine

      No, I see quite clearly that I have 14 litres of milk, not 20 litres of milk. Even a young kid can count up and tell you that

      it just depends on how you rearrange things

      Correctly or not

      our operators is just convention

      The notation is, the rules aren’t

      Something in between would be requiring parentheses around every operator, to enforce order

      No it wouldn’t. You know we’ve only been using brackets in Maths for 300 years, right? Order of operations is much older than that

      Such as (2+(3*4))

      Which is exactly how they did it before we started using Brackets in Maths 😂 2+3x4=2+3+3+3+3=14, not complicated.

      • SkyeStarfall@lemmy.blahaj.zone
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        2 months ago

        I mean, it is pretty clear here that you do not really understand the purpose of notation, nor what maths is. Notation is just a constructed language to convey a mathematical idea, it’s malleable

        And yeah, it’s easy to just say “this page is wrong!” without any further argument. Nothing you referenced proved the convention as law, and neither is there any mathematical basis for any proof, because it simply is nonsensical to “prove” a notation. Have another source for this being convention https://www.themathdoctors.org/order-of-operations-why/ or https://math.stackexchange.com/questions/884765/mathematical-proof-for-order-of-operations. If you want a book about this, then there’s https://en.wikipedia.org/wiki/Bronshtein_and_Semendyayev that is cited by wikipedia. I’m sure you could also find stuff about this in a set theory book. Though good luck understanding them without sufficient experience in high-level maths

        Really though, maths is so much more than “3+5=8 because that’s the correct answer!” But why is it the correct answer? In what context? What is the definition of addition? How can you prove that 1+1=2 from fundamental axioms? This is harder to answer than you might think.

        • I mean, it is pretty clear here that you do not really understand the purpose of notation,

          says person who doesn’t understand that there is only one possible answer to 2+3x4. Even kids who are still counting up know what it is

          Notation is just a constructed language to convey a mathematical idea, it’s malleable

          Yep, and the rules aren’t. 2+3x4 can only ever equal 14. In Germany it’s written 2+3.4, and it’s still equal to 14, because the rules are universal

          Nothing you referenced proved the convention as law

          says person ignoring the textbook screenshots explaining why it’s a Law 🙄

          neither is there any mathematical basis for any proof

          Yes there is. See textbook screenshots 🙄

          it simply is nonsensical to “prove” a notation

          It proves the rules 🙄

          Have another source for this being convention https://www.themathdoctors.org/order-of-operations-why/

          Read the comments and you’ll find multiple people telling him he is wrong, with references 😂 His usual comeback is “well, that doesn’t prove that it’s taught everywhere”, yeah only that they ALL say the same thing! 😂 And he even admitted at one point he couldn’t find his rule in any Maths textbooks. 😂 I even tried to tell him myself, and he deleted my comment because I proved he was wrong 😂

          or https://math.stackexchange.com/questions/884765/mathematical-proof-for-order-of-operations.

          Is well-known to be overridden with people who do not know how to do order of operations 😂 On Mastodon I’ve seen people asking where is a better place to take Maths problems

          If you want a book about this

          I have plenty of Maths textbooks, which for some reason you refuse to look in

          there’s https://en.wikipedia.org/wiki/Bronshtein_and_Semendyayev that is cited by wikipedia.

          “comprehensive handbook” - so, yet again, not a Maths textbook 🙄

          “first published in 1945 in Russia” - the order of operations rules are older than 1945 😂

          “frequently used guide for scientists, engineers, and technical university students” - notably no mention of Mathematicians

          I’m sure you could also find stuff about this in a set theory book

          and you could find this in a high school Maths textbook

          Though good luck understanding them without sufficient experience in high-level maths

          You know teachers here are required to have a Masters in Maths right?? 😂

          But why is it the correct answer?

          Count up and find out, or use some Cuisenaire rods. This is how young kids learn to do it

          In what context?

          The context of Addition 🙄

          What is the definition of addition?

          1+1=2, then inductively proven for all subsequent numbers

          How can you prove that 1+1=2 from fundamental axioms?

          It’s true by definition

          This is harder to answer than you might think

          Not hard at all. 1+1=2 by definition, then the rest of the numbers are proven inductively. You know there are several species of animals that also know how to count, right?