Understanding Roman Numerals

Roman numerals originated in ancient Rome and were used throughout the Roman Empire. Though largely replaced by Arabic numerals, they're still used for clock faces, book chapters, movie sequels, and formal documents.

The Seven Basic Symbols

Roman numerals use seven letters from the Latin alphabet:

• I = 1 (unus)
• V = 5 (quinque)
• X = 10 (decem)
• L = 50 (quinquaginta)
• C = 100 (centum)
• D = 500 (quingenti)
• M = 1000 (mille)

Additive Principle

In general, numerals are added from left to right in descending order. For example, XVII = 10 + 5 + 1 + 1 = 17.

Subtractive Principle

When a smaller numeral appears before a larger one, it's subtracted. This applies in specific cases:

• IV = 4 (5 - 1)
• IX = 9 (10 - 1)
• XL = 40 (50 - 10)
• XC = 90 (100 - 10)
• CD = 400 (500 - 100)
• CM = 900 (1000 - 100)

Limitations

Standard Roman numerals can only represent numbers from 1 to 3999. Numbers 4000 and above traditionally required special notation like vinculum (overline) to multiply by 1000.

Modern Uses

• Clock faces: IV or IIII for 4
• Outlines: I, II, III for main sections
• Movie sequels: Rocky III, Star Wars Episode IV
• Super Bowl: Super Bowl LVIII
• Monarchs: Queen Elizabeth II
• Year dates: MMXXIV = 2024