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Dozen is another word for the number twelve. The dozen may be one of the earliest primitive groupings, perhaps because there are approximately a dozen cycles of the moon or months in a cycle of the sun or year. The dozen is convenient because its multiples and divisors are convenient: 12 = 2 × 2 × 3, 3 × 4 = 2 × 6, 60 = 12 × 5, 360 = 12 × 30. The use of twelve as a base number, known as the duodecimal system (also as dozenal), probably originated in Mesopotamia (see also sexagesimal). Twelve dozen (12² = 144, the duodecimal 100) 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 (a dozen for each finger on both hands). A baker's dozen, also known as a long dozen, is thirteen.

The English word dozen [1] [2] [3] comes from the old form of the French word douzaine, meaning "a group of twelve" ("Assemblage de choses de même nature au nombre de douze" - (translation: A group of twelve things of the same nature as defined in the eighth edition of the Dictionnaire de l'Académie française). This French word [4] is a derivation from the cardinal number douze ("twelve", from Latin duodĕcim) and the collective suffix -aine (from Latin -ēna), a suffix also used to form other words with similar meanings such as quinzaine (a group of fifteen), vingtaine (a group of twenty), centaine (a group of one hundred), etc. These French words have synonymous cognates in Spanish: docena [5][6][7], quincena, veintena, centena, etc. English dozen, French douzaine, German Dutzend, Dutch dozijn and Spanish docena, are also used as indefinite quantifiers to mean "about twelve" or "many" (as in "a dozen times", "dozens of people").

Some historians believe^{[weasel words]} that the base twelve was important because it counts the bones in the fingers, instead of the entire finger. Each finger except for the thumb is divided in three bones, four fingers lets a person count up to 12 and two hands lets a person count up to 24. Using both hands with the decimal base system only allows counting to ten, one visual option for each finger (including the thumb). This method for accounting was introduced by the Babylonians and it's still in use today^{[citation needed]}.

[edit] See also

• Base twelve
• Number 12
• Baker's dozen
• Decimal dozen