Keystones — Capstone
Five GCSE retrieval questions · 5 September 2025 · 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 + 2.2x
Answer: (x + 1.1)² - 1.21 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 26cm, b = 24cm, angle = 70°
Answer: 293.2cm² -
4. Ratio Combining two ratios
a:b is 1:2 and b:c is 1:2. Find a:b:c.
Answer: 2:4:8 -
5. Statistics Averages and range
Find the mean, median and range of: 85, 95, 87, 68, 92, 63, 95, 88
Answer: Mean = 84.1, Median = 88, Range = 32