Keystones — Capstone
Five GCSE retrieval questions · 21 December 2025 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √243
Answer: 9√3 -
2. Algebra Completing the square
Complete the square: x² + 3.2x
Answer: (x + 1.6)² - 2.56 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 13cm, b = 26cm, angle = 40°
Answer: 108.6cm² -
4. Ratio Combining two ratios
a:b is 1:2 and b:c is 4:3. Find a:b:c.
Answer: 2:4:3 -
5. Statistics Averages and range
Find the mean, median and range of: 38, 14, 34, 19, 97, 88, 59, 76
Answer: Mean = 53.1, Median = 59, Range = 83