Dozen
The use of twelve as a base number, known as the duodecimal system (also as dozenal), originated in Mesopotamia (see also sexagesimal). This could come from counting on one's fingers by counting each finger bone with one's thumb.[citation needed] Using this method, one hand can count to twelve, and two hands can count to 144. Twelve dozen (122 = 144) are known as a gross; and twelve gross (123 = 1,728, the duodecimal 1,000) are called a great gross, a term most often used when shipping or buying items in bulk. A great hundred, also known as a small gross, is 120 or ten dozen.
Dozen-3