MathematicsClass 6Knowing Our Numbers
Roman Numerals
Learning the basic symbols and rules to write and interpret Roman numerals up to standard limits.
Class 6 · MathematicsCBSE & ICSE
Definition
Roman numerals are a system of numerical notations used by the ancient Romans, based on certain letters of the alphabet as figures. The fundamental symbols are I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
Key formula
Rules: Symbols can be repeated up to 3 times; smaller symbol left of a larger means subtraction; smaller symbol right means addition.
Worked examples
1
Write 73 in Roman numerals: LXXIII (70 + 3 = LXX + III).
2
Convert XLIX to Hindu-Arabic: XL is 50 - 10 = 40, IX is 10 - 1 = 9, so 40 + 9 = 49.
3
Write 95 in Roman numerals: XCV (90 + 5 = XC + V).
Common mistakes
- • Repeating a symbol more than three times (e.g., writing 40 as XXXX instead of XL).
- • Subtracting symbols that are not allowed (e.g., subtracting V, L, or D).
- • Adding the smaller value to the left instead of subtracting it.