Fundamental Rules of Roman Numerals
Roman numerals rely on specific additive and subtractive rules:
- Additive Rule: If a symbol is placed after a larger or equal symbol, its value is added. E.g., VIII = 5 + 1 + 1 + 1 = 8; XV = 10 + 5 = 15.
- Subtractive Rule: If a smaller symbol is placed before a larger symbol, its value is subtracted. E.g., IV = 5 - 1 = 4; IX = 10 - 1 = 9; XC = 100 - 10 = 90.
- Limits on Repetition: A symbol can be repeated at most three times consecutively. For example, IIII is not used; instead, write IV.
Typical Conversion Examples
Here are some common Roman numeral values for reference:
- 1994: MCMXCIV (M = 1000, CM = 900, XC = 90, IV = 4)
- 2024: MMXXIV (M + M = 2000, X + X = 20, IV = 4)
- 3999: MMMCMXCIX (The highest standard numeral without using overlines)