Roman numerals

What are Roman Numerals?

Roman numerals are a numeral system originating in ancient Rome, using combinations of letters from the Latin alphabet (I, V, X, L, C, D, M).

Basic Symbols and Values

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000.

Rule 1: Repetition

Symbols I, X, C, and M can be repeated (up to three times) for addition (e.g., III = 3, XX = 20).

Rule 2: Addition

If a smaller number is to the right of a larger number, add the smaller number (e.g., VI = 5 + 1 = 6).

Rule 3: Subtraction

If a smaller number is to the left of a larger number, subtract the smaller number (e.g., IV = 5 - 1 = 4).

Rule 4: Special Subtractions

When I, X, or C is placed before V, L, or D, the smaller number is subtracted from the larger (e.g., IX = 9, XL = 40).