How Roman Numerals Work
Roman numerals use seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). Numbers are formed by combining symbols from largest to smallest, left to right.
Subtractive Notation
When a smaller value precedes a larger one, it's subtracted:
- IV = 4 (5 − 1), IX = 9 (10 − 1)
- XL = 40 (50 − 10), XC = 90 (100 − 10)
- CD = 400 (500 − 100), CM = 900 (1000 − 100)
Frequently Asked Questions
What's the largest Roman numeral? In standard notation, 3,999 (MMMCMXCIX). With a vinculum (overline = ×1000), numbers up to 3,999,999 are possible.
Is there a zero in Roman numerals? No, the Romans had no symbol for zero. The concept of zero came later from Indian/Arabic mathematics.