this post was submitted on 12 Dec 2023
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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] 5 points 1 year ago* (last edited 1 year ago) (1 children)

Def not a math major (BS/PharmD), but your explanation was like seeing through a visual illusion for the first time! lol

I was always taught PEMDAS growing up, and that the MD and the AS was read left to right in an equation like above. But stating the division as a fraction completely changes my mind now about how this calculation works. I think what would happen in a calculation I use every day if the former was used.

Example: Cockcroft-Gault Equation (estimation of renal function)

(140-age)(kg) / 72(SCr) vs (140-age) X kg ➗72 X SCr

In the first eq (correct one) an 80yo patient who weighs 65kg and has an SCr ~ 1.5 = 36.11

In the latter it = 81.25 (waaay too high for an 80yo lol)

edit: calculation variable

[–] [email protected] 1 points 9 months ago

But stating the division as a fraction completely changes my mind now about how this calculation works

But division and fraction aren't the same thing - the former separates terms, the latter is a single term.

(140-age)(kg) / 72(SCr) vs (140-age) X kg ➗72 X SCr

The different answers for these two isn't because of / vs ➗, but because in the second one you have added extra multiplications in, thus breaking up some of the terms, and SCr has consequently been flipped from being in the denominator to being in the numerator. i.e. AK/72Scr vs. AK/72xSCr.