Roman numerals

The system of Roman numerals is a numeral system originating in ancient Rome, and was adapted from Etruscan numerals. The system used in antiquity was slightly modified in the Middle Ages to produce the system we use today.

Alternate forms

In the Middle Ages, Latin writers used a horizontal line above a particular numeral to represent one thousand times that numeral, and additional vertical lines on both sides of the numeral to denote one hundred times the number, as in these examples:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

: {{overline|I}} for one thousand

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

: {{overline|V}} for five thousand

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

: |{{overline|I}}| for one hundred thousand

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

: |{{overline|V}}| for five hundred thousand

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The same overline was also used with a different meaning, to clarify that the characters were numerals. Sometimes both underline and overline were used, e. g. {{overline|MCMLXVII}}.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Sometimes 500, usually D, was written as I followed by an apostrophus, resembling a backwards C (Ɔ), while 1,000, usually M, was written as CIƆ. This is believed to be a system of encasing numbers to denote thousands (imagine the Cs as parentheses). This system has its origins from Etruscan numeral usage. The D and M symbols to represent 500 and 1,000 were most likely derived from IƆ and CIƆ, respectively.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

An extra Ɔ denoted 500, and multiple extra Ɔs are used to denote 5,000, 50,000, etc. For example:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Sometimes CIƆ was reduced to an lemniscate symbol (infty) for denoting 1,000. John Wallis is often credited for introducing this symbol to represent infinity, and one conjecture is that he based it off of this usage, since 1,000 was hyperbolically used to represent very large numbers.

Related Topics:
Lemniscate - John Wallis - Hyperbolically

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In medieval times, before the letter j emerged as a distinct letter, a series of letters i in Roman numerals was commonly ended with a flourish; hence they actually looked like ij, iij, iiij, etc. This proved useful in preventing fraud, as it was impossible, for example, to add another i to vij to get viij. This practice is now merely an antiquarian's note; it is never used. (It did, however, lead to the Dutch diphthong IJ.)

Related Topics:
Dutch - Diphthong - IJ

~ ~ ~ ~ ~ ~ ~ ~ ~ ~