What are Roman numerals?

Roman numerals are an ancient numeral system that originated in Rome and uses seven letters from the Latin alphabet to represent fixed values. The system relies mainly on an additive principle, though subtraction is used when a smaller symbol precedes a larger one. Although they were largely replaced by the positional Hindu-Arabic numeral system starting in the 14th century, they continue to be used today in specific contexts such as clock faces, monuments, and film copyright dates.

What we know

• The modern style of Roman numerals uses seven letters from the Latin alphabet as symbols: I for 1, V for 5, X for 10, L for 50, C for 100, D for 500, and M for 1000. [3]
• Roman numerals are based on the additive principle, where the value of a numeral phrase is the sum of the individual values of each letter. [3]
• Subtraction is implied when a smaller numeral symbol precedes a larger one, such as IV representing 5 minus 1. [3]
• From the 14th century onward, Roman numerals began to be replaced across Europe by the positional Hindu-Arabic numeral system. [2, 3]

Where to go next

• compared withHow do Arabic numerals work?
• whoHow did Fibonacci help spread Arabic numerals in Europe?
• the bigger pictureWhat are Greek numerals?
• a case in pointWhere are Roman numerals still used today?
• an unexpected connectionHow did Babylonian cuneiform numerals function?

Sources

• [1]Arabic numeral (Wikidata Q29961325) · CC0 1.0
• [2]Arabic numerals · CC BY-SA 4.0
• [3]Roman numerals · CC BY-SA 4.0
• [4]Greek numerals · CC BY-SA 4.0
• [5]Babylonian cuneiform numerals · CC BY-SA 4.0