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