Keystones — Capstone
Five GCSE retrieval questions · 9 December 2025 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √200
Answer: 10√2 -
2. Algebra Completing the square
Complete the square: x² + 2x
Answer: (x + 1)² - 1 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 20cm, b = 15cm, angle = 79°
Answer: 147.2cm² -
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: 78, 48, 38, 88, 54, 84, 38, 32, 45
Answer: Mean = 56.1, Median = 48, Range = 56