Keystones — Cornerstone
Five GCSE retrieval questions · 12 December 2025 · mathsvault.uk/keystones
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1. Number
Calculate: 3 + (-9)
Answer: -6 -
2. Algebra
Solve: x + 9 = 26
Answer: x = 17 -
3. Geometry
Calculate perimeter: two sides are 15cm and 6cm at right angles
Answer: 37.2cm -
4. Ratio
Simplify: 20:12:24
Answer: 5:3:6 -
5. Statistics
Calculate the mean of: 43, 37, 27, 30, 19, 29
Answer: 30.8