NUMBER

Roman Numerals

Learn the reliable method for roman numerals, then apply it to 11+ exam-style questions.

1 · WHAT YOU NEED TO KNOW

The idea

Roman numerals combine standard symbols according to addition and subtraction rules.

Picture itUse the Roman numeral chart
2 · THE METHOD

Follow these steps

  1. Read paired subtraction forms such as IV, IX, XL and XC first.
  2. Add the remaining symbol values from left to right.
  3. Check that the numeral uses the standard order.
3 · WORKED EXAMPLES

See the method in action

Example 1

An archive box has the ordinary-number code 45. Which Roman-numeral label records this code correctly?

  1. XLV represents 45.
  2. Add symbols in descending order; subtract a smaller symbol only when it comes immediately before a larger one.
Answer: XLV
Example 2

Two old catalogue labels read LXXVIII and LXXXI. A replacement code is twice the sum of their ordinary-number values. What is the replacement code?

  1. Decode LXXVIII as 78 and LXXXI as 81.
  2. Their sum is 78 + 81 = 159.
  3. Double that sum to obtain 159 × 2 = 318.
Answer: 318
4 · ELEVENSPRINT TIP

A useful shortcut

Check that the numeral uses the standard order.

5 · COMMON MISTAKES

Watch out for these

6 · TRY IT YOURSELF

Three fresh questions

Ready to check the method? You will get three fresh, validated questions.