Trading and Numbers

The ease of a number's divisibility would affect how items were grouped where trading, exchanging, bartering, buying and selling are concerned. This is so a person could break down a group into smaller whole subgroups. So we would expect a grouping number used in trading to have many factors. 12 was such a number and it does have the most factors of any number around its size. It has more factors ( 12,6,4,3,2,1 ) than 10 ( 10,5,2,1).

Today we still use a dozen (12) for grouping items. An inch is 1/12 of a foot. In fact, although the ounce used in the present English system of measurement is 1/16 of a pound, the ounce began as 1/12 of a pound. A Troy ounce today is 1/12 of a Troy pound, whereas the English measurement system uses an Avoidupois ounce as 1/16 of an Avoidupois pound (see convert.htm). The word ounce began as meaning 1/12 of something.

The Roman Duodecimal system was a fractional system that used only the factors of 12 as fractional divisions.

As well as being easily divided, 12 was multiplied to make larger groups. See base12 (Duodecimal) and base60 (Sexagesimal).

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Last update on 01/26/98