Convert Roman numerals.
Convert numbers to and from Roman numerals.

🙂 = Correct, ☹️ = Incorrect

📌 Rules

• Know the 7 basic Roman numeral symbols:

– I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000.

• Addition Rule (symbols of equal or decreasing value): When a symbol appears after one of equal or greater value, add their values together (e.g. VI = 5 + 1 = 6; CLXX = 100 + 50 + 10 + 10 = 170).

• Subtraction Rule (smaller symbol before a larger symbol): When a smaller symbol appears before a larger symbol, subtract the smaller value from the larger value:

– IV = 4, IX = 9

– XL = 40, XC = 90

– CD = 400, CM = 900

• Build numbers by place value: Break thousands, hundreds, tens, and units into separate parts (e.g. 1,984 = 1000 + 900 + 80 + 4 = M + CM + LXXX + IV = MCMLXXXIV).

💡 Tips

• Memorise the subtractive pairs: Only six subtractive pairs are allowed in Key Stage 2: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900).

• Quick typing on our platform: Typing your answer is designed to be super quick and simple! When writing Roman numerals, type uppercase capital letters like XIV, CDL, or MMXXVI. When converting to numbers, type plain digits like 14, 450, or 2026 without adding spaces or extra symbols.

⚠️ Warnings

• Never repeat a symbol more than 3 times in a row: Write 4 as IV (not IIII) and 40 as XL (not XXXX).

• Never subtract V, L, or D: Symbols representing 5, 50, or 500 are never used subtractively (e.g. write 15 as XV, never VVV or VX).