Roman numerals is a symbols used in a system of numerical notation based on the ancient Roman system.
The symbols are I, V, X, L, C, D, and M, standing respectively for 1, 5, 10, 50, 100, 500, and 1,000 in the Arabic numeral system. A symbol placed after another of equal or greater value adds its value, e.g., II = 1 + 1 = 2 and LVIII = 50 + 5 + 1 + 1 + 1 = 58.
Usually only three identical symbols can be used consecutively; to express numbers beginning with a 4 or a 9, a symbol is placed before one of greater value to subtract its value, e.g., IV = −1 + 5 = 4, XC = −10 + 100 = 90, and MCMLXXXIX = 1,000 −100 + 1,000 + 50 + 10 + 10 + 10 −1 +10 = 1,989.
The exceptions are 4,000, which is sometimes written as MMMM, and clocks, which usually display 4 as IIII. A bar called a vinculum placed over a number multiplies is valued by 1,000.
| Numerals | |
|---|---|
| Arabic | Roman |
| 1 | I |
| 2 | II |
| 3 | III |
| 4 | IV |
| 5 | V |
| 6 | VI |
| 7 | VII |
| 8 | VIII |
| 9 | IX |
| 10 | X |
| 11 | XI |
| 12 | XII |
| 13 | XIII |
| 14 | XIV |
| 15 | XV |
| 16 | XVI |
| 17 | XVII |
| 18 | XVIII |
| 19 | XIX |
| 20 | XX |
| 21 | XXI |
| 22 | XXII |
| 23 | XXIII |
| 24 | XXIV |
| 30 | XXX |
| 40 | XL |
| 50 | L |
| 60 | LX |
| 70 | LXX |
| 80 | LXXX |
| 90 | XC |
| 100 | C |
| 101 | CI |
| 102 | CII |
| 200 | CC |
| 300 | CCC |
| 400 | CD |
| 500 | D |
| 600 | DC |
| 700 | DCC |
| 800 | DCCC |
| 900 | CM |
| 1,000 | M |
| 1,001 | MI |
| 1,002 | MII |
| 1,900 | MCM |
| 2,000 | MM |
| 2,001 | MMI |
| 2,002 | MMII |
| 2,100 | MMC |
| 3,000 | MMM |
| 4,000 | IV, MMMM, or MV |
| 5,000 | V |