Solving scaling problems with ratio made simple
21 October 2026
Scaling problems in 11+ maths
Scaling problems with ratios ask children to use relationships between numbers to work out real-life sizes, distances or quantities. These questions are common in 11+ GL and CEM exams and help build strong reasoning skills.
Step 1: Identify the scale and the given measurement
Begin by reading the question carefully. Look for the scale (such as 1:5) and the measurement given on the diagram or in the problem.
Step 2: Write the scale as a ratio
Express the scale as a clear ratio. For example, 1:5 means 1 unit on the drawing represents 5 units in real life.
Worked example
A map uses a scale of 1:5. A road measures 4 cm on the map. How long is the road in real life?
1. The scale is 1:5 and the map measurement is 4 cm.
2. 1 cm on the map equals 5 cm in real life.
3. Multiply the map measurement by the scale factor: 4 × 5 = 20.
The correct answer is 20 cm.
Step 3: Multiply to find the real measurement
Take the measurement from the drawing and multiply it by the scale factor. This gives the actual length or size in real life.
Helping your child practise
Encourage your child to check they are multiplying by the correct scale factor and to label their answers with the right units. Practising a range of examples builds confidence.
Key insight: Scaling problems often test careful reading and unit awareness as much as calculation. Remind your child to double-check which value represents the real measurement and which is the scaled version.
