Brackets come first, the order of operations for the division and multiplication is the same. The leftmost number takes precedence. You're multiplying the two rightmost numbers. 6/2*(1+2)
= 6/23
= 33
= 9
No extra brackets are added

[–] onlooker@lemmy.ml 3 points 2 years ago

Welp, I guess it's a good thing I never became a math teacher, because the way we were taught was to not only do the parentheses first, but also multiply the result with the number before the parentheses and then apply all other operations. Additionally, we were never taught the rule that the leftmost number takes precedence.

I never thought I'd be debating math problems rather than solving them, but here we are. Now if you'll excuse me, I have a sudden urge to play Math Blaster.

[–] dragnucs@lemmy.ml 3 points 2 years ago* (last edited 2 years ago) (1 children)

The two equations are different. The order is not the same when writing the multiplication sign and when omitting it. When omitted, it takes precedence.

6÷2×(2+1) ≠ 6÷2(2+1).

Imagine it like a÷bc versus a÷b×c.

The variable "a" is a single term and "bc" is a single term too. "bc" is the same as (b)(c) but not the same as b×c when speaking of operations order.

[–] drop@lemmy.ml 2 points 2 years ago* (last edited 2 years ago)

Hmm interesting. I've never heard that omitting the multiplication sign affects the order of operations. It could be that it's taught differently in different places. I'd probably interpret a/bc as (a/b)*c, though I'd be a bit confused seeing it written without parentheses.