What's something that sounds made up, but is completely true?

TonyHawksPoTater@kbin.social to Moving to: m/AskMbin!@kbin.social – 0 points –

I'll start: The Red Hot Chili Peppers are three years older than Guns N' Roses.

2

0.999... (infinite nines) and 1 are equal. They are two representations of the same number, like 0.5 and 1/2 (one half) are.

While it's easy to prove rigorously I think the easiest way to think about it is to think what number/numbers could go between 0.9 repeating and 1.
I guess that it also requires a second thought experiment that if no numbers can go between two numbers, those two numbers must be the same.

edit: this might be even easier:

1/3 = 0.333... -> multiply both sides by 3
3/3 = 0.999...
1 = 0.999...