this post was submitted on 03 Dec 2023
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[–] queue@lemmy.blahaj.zone 0 points 11 months ago* (last edited 8 months ago) (1 children)

For anyone like me who has math as their worst subject: PEMDAS.

PEMDAS is an acronym used to mention the order of operations to be followed while solving expressions having multiple operations. PEMDAS stands for P- Parentheses, E- Exponents, M- Multiplication, D- Division, A- Addition, and S- Subtraction.

So we gotta do it in the proper order. And remember, if the number is written like 2(3) then its multiplication, as if it was written 2 x 3 or 2 * 3.

So we read 8/2(2+2) and need to do the following;

  • Read the Parentheses of (2 + 2) and follow the order of operations within them, which gets us 4.
  • Then we do 2(4) which is the same as 2 x 4 which is 8
  • 8 / 8 is 1.

The answer is 1. The old calculator is correct, the phone app which has ads backed into it for a thing that all computers were invented to do is inaccurate.

[–] a_fine_hound@lemmy.world 0 points 11 months ago* (last edited 11 months ago) (1 children)

Well that's just wrong... Multiplication and division have equal priorities so they are done from left to right. So: 8 / 2 * (2 + 2)=8 / 2 * 4=4 * 4=16

[–] nutcase2690@lemmy.dbzer0.com 0 points 11 months ago (1 children)

Not quite, pemdas can go either from the left or right (as long as you are consistent) and division is the same priority as multiplication because dividing by something is equal to multiplying by the inverse of that thing... same as subtraction being just addition but you flip the sign.

8×1/2=8/2 1-1=1+(-1)

The result is 16 if you rewrite the problem with this in mind: 8÷2(2+2)=8×(1/2)×(2+2)

[–] SmartmanApps@programming.dev 0 points 8 months ago

8÷2(2+2)=8×(1/2)×(2+2)

No, that's wrong. 2(2+2) is a single term, and thus entirely in the denominator. When you separated the coefficient you flipped the (2+2) into the numerator, hence the wrong answer. You must never add multiplication signs where there are none.