Keystones — Lintel
Five GCSE retrieval questions · 21 March 2026 · mathsvault.uk/keystones
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1. Number Error intervals
A value is 24.4 (to dp). State the error interval
Answer: 24.35 ≤ x < 24.45 -
2. Algebra Expanding two brackets
Expand: (x + 4)(x - 3)
Answer: x² + x - 12 -
3. Geometry Area of a circle
A circle has area 706.9cm². Find its radius (dp)
Answer: 15cm -
4. Ratio One amount as a percentage of another
Express 65 as a percentage of 267
Answer: 24.34% -
5. Statistics Averages and range
Find the mean, mode, median and range of: 31, 28, 28, 42, 26
Answer: Mean = 31, Mode = 28, Median = 28, Range = 16