The Roman numeral system is a cousin of Etruscan numerals. Use of Roman numerals continued after the decline of the Roman Empire. From the 14th century on, Roman numerals began to be replaced in most contexts by more convenient Hindu-Arabic numerals; however this process was gradual, and the use of Roman numerals in some minor applications continues to this day.
Numbers are formed by combining symbols together and adding the values. So II is two ones, i.e. 2, and XIII is a ten and three ones, i.e. 13. There is no zero in this system, so 207, for example, is CCVII, using the symbols for two hundreds, a five and two ones. 1066 is MLXVI, one thousand, fifty and ten, a five and a one.
Symbols are placed from left to right in order of value, starting with the largest. However, in a few specific cases, to avoid four characters being repeated in succession (such as IIII or XXXX) these can be reduced using subtractive notation as follows:
- the numeral I can be placed before V and X to make 4 units (IV) and 9 units (IX respectively)
- X can be placed before L and C to make 40 (XL) and 90 (XC respectively)
- C can be placed before D and M to make 400 (CD) and 900 (CM) according to the same pattern
An example using the above rules would be 1904: this is composed of 1 (one thousand), 9 (nine hundreds), 0 (zero tens), and 4 (four units). To write the Roman numeral, each of the non-zero digits should be treated separately. Thus 1,000 = M, 900 = CM, and 4 = IV. Therefore, 1904 is MCMIV.
Below are some examples of the modern use of Roman Numerals.
1954 as MCMLIV (Trailer for the movie The Last Time I Saw Paris)
1990 as MCMXC (The title of musical project Enigma's debut album MCMXC a.D., named after the year of its release.)
2014 as MMXIV - the year of the games of the XXII (22nd, Winter) Olympiad (in Sochi)