Learn Roman numerals with building blocks

Build Roman numerals from small known parts. Begin with I, V and X, then introduce the subtraction pairs IV and IX.

Worked example

To write 24, split it into 20 + 4. Twenty is XX and four is IV, so 24 is XXIV. Compare 26: XX + VI = XXVI. In 94, use 90 + 4: XC + IV = XCIV. Read each block before joining them.

Try it step by step

1. Roman numeral builder

   Read the units, diagram or calculation. Work it out and choose the answer; the explanation shows the method.

A useful hint

Use the standard pairs IV, IX, XL, XC, CD and CM. Avoid inventing subtraction pairs such as IL for 49; write XLIX.

Simple activities, gentle encouragement, and room to explore at your own pace. Big buttons and simple controls on phones, tablets, and computers.

Questions to discuss

• What did you notice first?
• Can you show another example?
• How did you check your answer?

Games to practise