this post was submitted on 03 Dec 2023
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[–] subignition@kbin.social 65 points 2 years ago* (last edited 2 years ago) (5 children)

[...] the question is ambiguous. There is no right or wrong if there are different conflicting rules. The only ones who claim that there is one rule are the ones which are wrong!

https://people.math.harvard.edu/~knill/pedagogy/ambiguity/index.html

As youngsters, math students are drilled in a particular
convention for the "order of operations," which dictates the order thus:
parentheses, exponents, multiplication and division (to be treated
on equal footing, with ties broken by working from left to right), and
addition and subtraction (likewise of equal priority, with ties similarly
broken). Strict adherence to this elementary PEMDAS convention, I argued,
leads to only one answer: 16.

Nonetheless, many readers (including my editor), equally adherent to what
they regarded as the standard order of operations, strenuously insisted
the right answer was 1. What was going on? After reading through the
many comments on the article, I realized most of these respondents were
using a different (and more sophisticated) convention than the elementary
PEMDAS convention I had described in the article.

In this more sophisticated convention, which is often used in
algebra, implicit multiplication is given higher priority than explicit
multiplication or explicit division, in which those operations are written
explicitly with symbols like x * / or ÷. Under this more sophisticated
convention, the implicit multiplication in 2(2 + 2) is given higher
priority than the explicit division in 8÷2(2 + 2). In other words,
2(2+2) should be evaluated first. Doing so yields 8÷2(2 + 2) = 8÷8 = 1.
By the same rule, many commenters argued that the expression 8 ÷ 2(4)
was not synonymous with 8÷2x4, because the parentheses demanded immediate
resolution, thus giving 8÷8 = 1 again.

This convention is very reasonable, and I agree that the answer is 1
if we adhere to it. But it is not universally adopted.

[–] EndlessApollo@lemmy.world 7 points 2 years ago

That's cool, but still wrong :3

[–] I_am_10_squirrels@beehaw.org 2 points 2 years ago

Exactly, explicit multiplication is part of the parenthesis so it comes first in order of operations

[–] SmartmanApps@programming.dev 1 points 1 year ago (1 children)

[…] the question is ambiguous. There is no right or wrong if there are different conflicting rules. The only ones who claim that there is one rule are the ones which are wrong!

https://people.math.harvard.edu/~knill/pedagogy/ambiguity/index.html

Yeah nah. Actual Maths textbooks and proofs - did you not notice the complete lack of references to textbooks in the blog? It's funny that he mentions Cajori though, given Cajori has a direct reference to Terms #MathsIsNeverAmbiguous

[–] subignition@kbin.social 1 points 1 year ago (1 children)

I think I'm gonna trust someone from Harvard over your as-seen-on-TV looking ass account, but thanks for the entertainment you've provided by trying to argue with some of the actual mathematicians in here

[–] SmartmanApps@programming.dev 1 points 1 year ago* (last edited 1 year ago)

I think I’m gonna trust someone from Harvard

So you're going with the appeal to authority argument - ok, got it.

But if you're gonna do that then make sure you check out Cajori's credentials, since that's, you know, who we both quoted.

argue with some of the actual mathematicians in here

You mean the dude who claimed to be, and was quoting wikipedia? BWAHAHAHAHA