Until you need to deal with decimals instead of floats, then you are going to hate yourself because you have to pull in some third party library because the language treats every single number as a float (and floating point errors are a lot more common than most people think even when they are adding together simple numbers).

I just did some ownership percentage stuff where it's not uncommon to go 16 decimal places out...working with JavaScript on this was a pain. Never thought I'd care about that .00000000000001 difference hah...