What are Roman Numerals?
Roman numerals are an ancient numeral system using letters to represent values. Developed by the Romans, they use combinations of letters (I, V, X, L, C, D, M) to express numbers from 1 to 3,999. While largely replaced by Arabic numerals (0-9), they remain in use for formal documents, clock faces, and historical references.
Key Features:
- I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000
- Additive Notation: VI = 6 (5 + 1), XIV = 14 (10 + 4)
- Subtractive Notation: IV = 4 (5 - 1), IX = 9 (10 - 1)
- Range: Supports 1 to 3,999
- Bidirectional: Convert in both directions
Roman Numeral Rules
Additive Principle
Letters are added together: VII = 7, XII = 12
Subtractive Principle
Smaller value before larger is subtracted: IV = 4, XL = 40
Repetition
I, X, C, M can repeat (max 3 times): III = 3, XXX = 30
Position Matters
Same letters in different positions have different values
Common Roman Numerals
| Arabic | Roman | Arabic | Roman |
|---|---|---|---|
| 1 | I | 50 | L |
| 4 | IV | 100 | C |
| 9 | IX | 500 | D |
| 10 | X | 1000 | M |
FAQ
Why use Roman numerals today?
They're used in formal documents, movie credits, clock faces, and historical references.
What's the maximum value?
The standard range is 1-3,999. Extended notations exist for larger numbers but aren't commonly used.
Is there a zero in Roman numerals?
No. Romans had no symbol for zero, which is one reason they were eventually replaced by Arabic numerals.