Number

Roman numeral

The letters have the following values:

I = 1

V = 5

X = 10

L = 50

C = 100

D = 500

M = 1000

Numbers are formed by combining letters togehter and adding or subtracting there values. All values is added except when smaller values precede larger values, the smaller values are then subtracted from the larger values. Some examples:

VI = 5 + 1 = 6

IX = -1 + 10 = 9

MCMXLIV = 1000 -100 + 1000 - 10 + 50 - 1 + 5 = 1944

There are a few more rules that must be met for a Roman number to be valid. They are:

1. The letters I, X, C, and M can be repeated three times in succession, but no more. D, L, and V can never be repeated.

2. I can be subtracted from V and X only. X can be subtracted from L and C only. C can be subtracted from D and M only. V, L, and D can never be subtracted.

3. Only one small-value symbol may be subtracted from any large-value symbol.

4. A number written in Arabic numerals can be broken into digits. For example, 1903 is composed of 1, 9, 0, and 3. To write the Roman numeral, each of the non-zero digits should be treated separately. In the above example, 1,000 = M, 900 = CM, and 3 = III. Therefore, 1903 = MCMIII.