Keystones — Capstone
Five GCSE retrieval questions · 17 February 2026 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √108
Answer: 6√3 -
2. Algebra Completing the square
Complete the square: x² + 4.4x
Answer: (x + 2.2)² - 4.84 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 21cm, b = 26cm, angle = 58°
Answer: 231.5cm² -
4. Ratio Combining two ratios
a:b is 3:2 and b:c is 3:4. Find a:b:c.
Answer: 9:6:8 -
5. Statistics Averages and range
Find the mean, median and range of: 53, 50, 31, 41, 69, 41, 21, 68
Answer: Mean = 46.8, Median = 50, Range = 48