this post was submitted on 03 Dec 2023
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[–] arisunz@lemmy.blahaj.zone 19 points 1 year ago (3 children)

this comment section illustrates perfectly why i hate maths so much lmao

love ambiguous, confusing rules nobody can even agree on!

[–] onion@feddit.de 23 points 1 year ago (3 children)

The problem isn't math, it's the people that suck at at it who write ambigous terms like this, and all the people in the comments who weren't educated properly on what conventions are.

[–] Swallowtail 5 points 1 year ago (1 children)

Yeah, you could easily make this more straightforward by putting parentheses around 8÷2. It's like saying literature sucks because Finnegans Wake is incomprehensible.

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

you could easily make this more straightforward by putting parentheses around 8÷2

But that would be a different expression with a different answer (16 rather than 1). This is the mistake made by the programmer of the e-calc - treats it as though there's extra brackets there when there isn't.

[–] loops 3 points 1 year ago (1 children)

Huge shout out to the jaded AF high school math teachers that don't give a fuck any more!

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

They do care. The issue is everyone argues about it without even asking Maths teachers about it to being with! I guarantee (I've seen it myself) literally every blog you read which says this is "ambiguous", without exception they never mention Maths textbooks or Maths teachers (because then they wouldn't be able to bombastically declare "This is ambiguous!").

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

write ambigous terms like this

It's not ambiguous

all the people in the comments who weren’t educated properly on what conventions are

Everyone was taught the rules of Maths - it's just a matter of who remembers them or not.

[–] 4am@lemm.ee 7 points 1 year ago (2 children)

PEMDAS

Parenthesis, exponents, multiplication, division, addition, subtraction.

The rule is much older than me and they taught it in school. Nothing ambiguous about it, homie. The phone app is fucked up. Calculator nailed it.

[–] hallettj 7 points 1 year ago (2 children)

The comment from subignition explains that the phone's answer, 16, is what you get by strictly following PEMDAS: the rule is that multiplication and division have the same precedence, and you evaluate them from left-to-right.

The calculator uses a different convention where either multiplication has higher priority than division, or where "implicit" multiplication has higher priority (where there is no multiply sign between adjacent expressions).

[–] I_am_10_squirrels 2 points 1 year ago (1 children)

But explicit multiplication is part of the parenthesis, so still comes before division or exponent

[–] hallettj 3 points 1 year ago (1 children)

The parentheses step only covers expressions inside parentheses. That's 2 + 2 in this case. The times-2 part is outside the parentheses so it's evaluated in a different step.

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

The parentheses step only covers expressions inside parentheses

No, it doesn't

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

16, is what you get by strictly following PEMDAS

except 1 is what you get from strictly following PEMDAS. If you got 16 then you missed one of more rules.

the rule is that multiplication and division have the same precedence, and you evaluate them from left-to-right

Go back and read your link again. You'll find they're obeying The Distributive Law. i.e. solve all brackets first, from inner-most out.

“implicit” multiplication

There's no such thing as implicit multiplication

[–] arisunz@lemmy.blahaj.zone 2 points 1 year ago* (last edited 1 year ago)

i know about pemdas and also my brother in christ half the people in the comments are saying the phone app is right lmao

edit: my first answer was 16

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

rules nobody can even agree on!

All the Maths textbooks agree