base 5 is a positional numeral system with five as its base. It uses 5 different digits for representing numbers. The digits for base 5 could be 0, 1, 2, 3, and 4.

base 9 is a positional numeral system with nine as its base. It uses 9 different digits for representing numbers. The digits for base 9 could be 0, 1, 2, 3, 4, 5, 6, 7, and 8.