11+ Maths: Solving Scaling Problems with Ratio (GL & CEM style)
26 October 2026
Why ratio and scaling matter in 11+ maths
Understanding ratio and scaling is key for many 11+ questions. These problems often appear in both GL and CEM style exams, testing how well your child can apply proportional thinking to real-life situations.
How to approach scaling problems with ratio
Start by identifying the scale or ratio in the question. The ratio shows the relationship between two amounts, such as the size of a model compared to the real object. Decide which value you know and which you need to find.
Worked example
A model car is built at a scale of 1:20. If the real car is 4 metres long, how long is the model?
Step 1: The scale 1:20 means 1 unit on the model equals 20 units on the real car.
Step 2: To find the model length, divide the real car's length by the scale factor.
4 metres ÷ 20 = 0.2 metres
Step 3: Convert to centimetres if needed. 0.2 metres × 100 = 20 cm.
The model car is 20 cm long.
Key insight: Mastering ratio and scaling questions helps children understand proportion, which is vital for many 11+ topics. These skills also support problem-solving in areas like recipes, maps, and models.
