How Roman Numerals Work
Roman numerals use seven symbols: I (1), V (5), X (10),L (50), C (100), D (500), and M (1000).
Addition Rule
When a smaller value follows a larger one, add them: VI = 5 + 1 = 6, XII = 10 + 1 + 1 = 12.
Subtraction Rule
When a smaller value precedes a larger one, subtract it: IV = 5 - 1 = 4, IX = 10 - 1 = 9, XL = 50 - 10 = 40.
Examples
- 2025 = MMXXV (1000 + 1000 + 10 + 10 + 5)
- 1999 = MCMXCIX (1000 + 900 + 90 + 9)
- 444 = CDXLIV (400 + 40 + 4)