Round a double-precision floating-point number to the nearest multiple of 10^n.
This library can solve one well known problem with JavaScript Number arithmetic imprecise, when, for example, 3.3 * 3 becomes 9.899999999999999, ugly.
Converts a number into a string, keeping a specified number of decimals.
Math.round with fixed, formats a number using fixed-point notation and returns a number.