What do these numbers represent? Your rounding rules seem utterly arbitrary, rounding 0.0205511 to 0.02 introduces an error of 2.8% and preserves only one significant digit, 8.8458e-119 to 8.84e-119 keeps three significant digits (and has an error of only 0.66%), and it's truncating, not rounding.

Simply chopping digits off numbers is usually a bad idea, because it distorts their meaning.

Anyway, for formatting you can use printf or sprintf, which you can use to for example to show the first three significant digits.