The decimal numeral system (also called base-ten positional numeral system, and occasionally called denary) is the standard system for denoting integer and non-integer numbers. It has ten as its base.
base 13
base 13 is a positional numeral system with thirteen as its base. It uses 13 different digits for representing numbers. The digits for base 13 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, and c.