Origin and history of hundred

"reckoning by twelves and powers of twelve," 1714, from Latin in duodecimo (folded) "in a twelfth" of a sheet, from ablative of duodecimus "twelfth" (from duodecim "twelve;" see dozen) + -al (1).

Divisions based on 10s are convenient for arithmetical calculation and computation of numbers. Duodecimal reckoning (as in ounces, inches) is better suited to practical use in weights and measures for material substances (food, drink).

Thus English, like many other Germanic languages, retains a shadow number system based on 12. Eleven and twelve ought to be the first numbers of the "teens" series. Their Old English forms, enleofan and twel(eo)f(an), are more transparent: "leave one" and "leave two."

Old English also had hund endleofantig for "110" and hund twelftig for "120." "One hundred" was hund teantig. The -tig formation (see -ty (1)) ran through 12 cycles, and could have bequeathed Modern English *eleventy ("110") and *twelfty ("120"), but already in Anglo-Saxon times it was being obscured.

Old Norse used hundrað for "120" and þusend for "1,200." Tvauhundrað was "240" and þriuhundrað was "360." Older Germanic legal texts distinguished a "common hundred" (100) from a "great hundred" (120).

Among all its conveniences, the decimal division has the great disadvantage of being itself divisible only by the numbers two and five. The duodecimal division, divisible by two, three, four, and six, would offer so many advantages over it, that while the French theory was in contemplation, the question was discussed, ... whether the number twelve should not be substituted for ten, as the term of the periodical return to the unit. [John Quincy Adams, "Report of the Secretary of State Upon Weights and Measures," 1821]

late 14c., "one hundred," from Latin centum "hundred" (see hundred). The meaning shifted 17c. to "hundredth part" under influence of percent. It was chosen in this sense April 18, 1786, in a Board of Treasury report, as a name for a U.S. currency unit (the hundredth part of a dollar) by the Continental Congress. Dime also first appears as a U.S. coin name in the same document.

The word cent first had been suggested by Robert Morris in 1782 under his original plan for a U.S. currency. Morris's system had an unnamed basic unit at a very small value, and 100 of these was to equal a cent. But the ratio of this cent to the dollar would have been about 144:1.

The Money Unit will be equal to a quarter of a Grain of fine Silver in coined Money. Proceeding thence in a decimal Ratio one hundred would be the lowest Silver Coin and might be called a Cent. [Jan. 15, 1782, Morris's report, included in the Financier's response to a resolution of the Continental Congress on currency exchange]

Thomas Jefferson's counterproposal, which won approval, built on Morris's but eliminated the basic unit and made the decimal system uniform throughout.

Before the cent, Revolutionary and colonial dollars were reckoned in ninetieths, based on the exchange rate of Pennsylvania money and Spanish coin.