Duodecimal

• abstract: The duodecimal system (also known as base-12 or dozenal) is a positional notation numeral system using twelve as its base. In this system, the number ten may be written as "A", "T" or "X", and the number eleven as "B" or "E" (another common notation, introduced by Sir Isaac Pitman, is to use a rotated "2" (ᘔ) for ten and a reversed "3" (ᘍ) for eleven).

以上来源于: WordNet