Roman Numerals

Roman numerals are a number system developed in ancient Rome that uses letters of the alphabet to represent values. The key symbols are: I (1), V (5), X (10), L (50), C (100), D (500) and M (1,000). Numbers are formed by combining these symbols. Generally, you add symbols together: VI = 6, XII = 12, LX = 60, MCXI = 1,111. However, there is a subtraction rule: when a smaller symbol appears directly before a larger one, subtract it. So IV = 4 (not IIII), IX = 9, XL = 40, XC = 90, CD = 400 and CM = 900. Roman numerals can only be repeated up to three times in a row — so 4 must be written as IV, not IIII. You still encounter Roman numerals on clock and watch faces, in the names of monarchs (King Charles III), film sequels, and sporting events like the Olympics and Super Bowl. Reading and writing Roman numerals up to 1,000 is a key Year 4 objective.