Keystones — Cornerstone
Five GCSE retrieval questions · 5 October 2026 · mathsvault.uk/keystones
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1. Number Highest common factor
Find the HCF of 18 and 15
Answer: 3 -
2. Algebra Substitution
If x = 2, calculate x² + 6x + 8
Answer: 24 -
3. Geometry Circumference of a circle
Calculate the circumference of a circle with radius 6cm
Answer: 37.7cm -
4. Ratio Percentage multipliers
What multiplier represents a 50% increase?
Answer: 1.5 -
5. Statistics Averages and range
Find the mean, median and range of: 16, 26, 40, 19, 26
Answer: Mean = 25.4, Median = 26, Range = 24