Duodecimal numbers are built out of the \(12\) digits, \(0,1,2,3,4,5,6,7,8,9,A\) and \(B\), although some people use other symbols such as an upside down \(1\) for \(A\) and an upside down \(2\) for \(B\).

The duodecimal system is a Base-12 number system.

Another name for the duodecimal number system is the dozenal number system.

The following are some examples of duodecimal numbers:

• The duodecimal number \(A\) is equal to the decimal number \(10\)
• The duodecimal number \(B\) is equal to the decimal number \(11\)
• The duodecimal number \(10\) is equal to the decimal number \(12\)
• The duodecimal number \(100\) is equal to the decimal number \(144\)
• The duodecimal number \(110\) is equal to the decimal number \(156\)
• The duodecimal number \(111\) is equal to the decimal number \(157\)
• The duodecimal number \(129AB\) is equal to the decimal number \(1 \times 12^4 + 2 \times 12^3 + 9 \times 12^2 + 10 \times 12 + 11 = 25,619\).