For a few months, I coded an arbitrary precision system using arrays just to get experience and to solve problems on Project Euler. I'm currently using the decimal number, although I have introduced binary and hexadecimal but on a limiting scale. I have coded addition, subtraction, multiplication, division, square root, power, factorial, etc. and I looking at ways to make it run faster and probably use less memory. I know that arrays aren't the most efficient way to code this kind of stuff, but it's supposed to be a starting point to more advance methods. So I was wondering if there is a more efficient way to do arbitrary precision using arrays. EDIT: Does a binary arbitrary execute faster than a decimal arbitrary?