If you care about numbers, do the math yourself. Learn how floating point numbers on computers work, and where they're likely to introduce problems.

The problem there being: to understand how floating point numbers on computers work, you have to understand how your particular architecture deals with floating point numbers -- as well as every other architecture your program might run on.

(There are multiple IEEE floating point standards, not to mention that a lot of hardware doesn't do any of them right)

I would suggest, in the spirit of your orriginal suggestion, that if you really care about precission, the best thing to do is to use an existing module designed to allow cross platform support for very precise mathematic operators (like Math::BigFloat) and if you really care about how the internals work, read the source.