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Percentages are reversible. 8% of 25 is the same as 25% of 8, and often one of them is much easier to do in your head.

It's obvious if you think about it, sure.

@ben @fribbledom I sort of knew that but never realized the implications?

@fribbledom this feels familiar like forgotten knowledge.

@fribbledom

This is excellent news

@fribbledom Wtf, never quite really realized it. I must've known but not this obvious. :D

@fribbledom @memethesis interpret % as an arithmetic operator

const % = 0.01

set mono

@memethesis @fakefred @fribbledom Why is the modulo math in my code suddenly not working!

@fribbledom 🤯🤯🤯

@fribbledom holy h*ck that's useful, I never realized...

@fribbledom this is genius how did I not know this already

@fribbledom wow, thats awsome!

@fribbledom Spot the typo. :) That first bit after 18/(18+1) should be 1/(1+1/18) not 1/(1+18).

@fribbledom what the FUCK

@fribbledom !!

That absolutely makes sense and I had absolutely never thought of that.

@Yulran @fribbledom me too, thanks for that information!

@funnypanja @fribbledom no. 2 is 8% of 25 because of my decision. Everything else was my stupid neighbors to blame.

@fribbledom you mean a*b=b*a or (a/100)*b=a*b/100 .. it sounds very boring stated that way.

I think this makes it a bit more readable:

a% of b = (a/100) * b = 0.01 * a * b

equals

b% of a = (b/100) * a = 0.01 * b * a

so 25 * 8 = 200 and 8 * 25 = 200, and 200 * 0.01 = 2.

therefore

25 percent of 8 is 2

and

8 percent of 25 is 2

right?

Exactly. I don't know why it would be news that 8*5 is the same as 5*8 and just move the decimal place to make sense. People do this all day when out shopping don't they.

@fribbledom I feel so sad that this has to be stated.

@fribbledom@mastodon.social I did a bunch of math to check but holy shit thanks

@fribbledom @anarchiv I stumbled across this when I was 8 and learnt the associative rule.

@fribbledom I see we saw the same askreddit thread

@fribbledom You can really see why this is true if you put it like this: 8% is the same as 8*0.01, so:

8% of 25 is 8*0.01*25, and

25% of 8 is 25*0.01*8

the birthday phenomenon

How many random people need to be at a party before there is a 50% chance that two of them share the same birthday?

Hint: it's a lot lower than most people think.

@carcinopithecus yes. (I'm not arguing and you don't have to be defensive.)

@isagalaev @fribbledom

When I see " * 25%", my mind translate it to "/ 4" without thinking. And the whole thing becomes 8 / 4

When I see " * 25%", my mind translate it to "/ 4" without thinking. And the whole thing becomes 8 / 4

@fribbledom I am deeply angry that I wasn't taught this in school.

@fribbledom and 25 is 25% of 100!

@fribbledom you can also often do something like 8 * 25 and move the comma two places left

@fribbledom 🤯🤯🤯

@fribbledom this hack is so useful!

@fribbledom No, I didn't. Thanks.

@fribbledom

Quellenangabe?

High school, 30 years ago 😂

Ben Lubar (any pronouns)@ben@lubar.me@fribbledom % is a mathematical constant equal to 0.01