Keystones — Capstone
Five GCSE retrieval questions · 30 October 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 + 2.2x
Answer: (x + 1.1)² - 1.21 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 27cm, b = 13cm, angle = 72°
Answer: 166.9cm² -
4. Ratio Combining two ratios
a:b is 1:2 and b:c is 2:3. Find a:b:c.
Answer: 2:4:6 -
5. Statistics Averages and range
Find the mean, median and range of: 97, 78, 48, 17, 84, 34, 45, 55, 31
Answer: Mean = 54.3, Median = 48, Range = 80