Keystones — Lintel
Five GCSE retrieval questions · 22 June 2026 · mathsvault.uk/keystones
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1. Number Error intervals
A value is 56.9 (to dp). State the error interval
Answer: 56.85 ≤ x < 56.95 -
2. Algebra Expanding two brackets
Expand: (x + 8)(x - 8)
Answer: x² + 0x - 64 -
3. Geometry Area of a circle
A circle has area 254.5cm². Find its radius (dp)
Answer: 9cm -
4. Ratio One amount as a percentage of another
Express 55 as a percentage of 280
Answer: 19.64% -
5. Statistics Averages and range
Find the mean, median and range of: 57, 92, 66, 45, 81, 82, 64, 70
Answer: Mean = 69.6, Median = 70, Range = 47