We started by comparing true Arabic numbers to the numbers we use in the West. We discussed the problems with Roman numbers--no zero and hit or miss computation. We discussed our decimal system with base 10 and 10 digits and showed how each place involved 10 to a power. Then we saw how binary works the same way except there are two digits (or bits). We then related binary to octal (base 8) and hexadecimal (base 16) systems.