this post was submitted on 12 Dec 2023
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6÷2(1+2) (programming.dev)
submitted 1 year ago* (last edited 1 year ago) by [email protected] to c/[email protected]
 

https://zeta.one/viral-math/

I wrote a (very long) blog post about those viral math problems and am looking for feedback, especially from people who are not convinced that the problem is ambiguous.

It's about a 30min read so thank you in advance if you really take the time to read it, but I think it's worth it if you joined such discussions in the past, but I'm probably biased because I wrote it :)

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[–] [email protected] 2 points 1 year ago (2 children)

yeah, our math profs taught if the 2( is to be separated from that bracket for the implied multiplication then you do that math first, because the 2(1+2) is the same as (1+2)+(1+2) and not related to the first 6.

[–] [email protected] 2 points 1 year ago* (last edited 1 year ago) (1 children)

So you were taught strong juxtaposition then, where the implicit multiplication takes priority?

[–] [email protected] 2 points 1 year ago (1 children)

if it was 6÷2x(2+1) they suggested do division and mult from left to right, but 6÷2(2+1) implied a relationship between the number outside the parenthesis and inside them, and as soon as you broke those () you had to do the multiplication immediately that is connected to them. Like some models of calculatora do. wasn't till a few yeara ago that I heard people were doing it differently.

[–] [email protected] 2 points 9 months ago

if it was 6÷2x(2+1) they suggested do division and mult from left to right, but 6÷2(2+1)

Correct! Terms are separated by operators and joined by grouping symbols, so 6÷2x(2+1) is 3 terms - 6, 2, and (2+1) - whereas 6÷2(2+1) is 2 terms - 6 and 2(2+1), and the latter term has a precedence of "brackets", NOT "multiplication". Multiplication refers literally to multiplication signs, which are only present in your first example (hence evaluated with a different order than your second example).

Also noted that the OP has ignored your comment, seeing as how you pointed out the unambiguous way to do it.

[–] [email protected] 0 points 10 months ago

2(1+2) is the same as (1+2)+(1+2)

You nearly had it. 2(1+2) is the same as (2x1+2x2). The Distributive Law - it's the reverse process to factorising.