You've already been pointed to the ** operator described in perlop, but I wanted to mention one other thing that may be relevant. How big are the numbers that you will be generating?

If the values you are using are small, ** will work fine. If your code may generate very large numbers, however, you might want to look at Math::BigInt. There is a performance penalty that could become significant, so if you find that speed is an issue then Math::BigInt::GMP might help.