Keystones — Lintel
Five GCSE retrieval questions · 16 March 2026 · mathsvault.uk/keystones
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1. Number Error intervals
A value is 49.2 (to dp). State the error interval
Answer: 49.15 ≤ x < 49.25 -
2. Algebra Expanding two brackets
Expand: (x - 6)(x - 3)
Answer: x² - 9x + 18 -
3. Geometry Area of a circle
A circle has area 78.5cm². Find its radius (dp)
Answer: 5cm -
4. Ratio One amount as a percentage of another
Express 26 as a percentage of 232
Answer: 11.21% -
5. Statistics Averages and range
Find the mean, mode, median and range of: 26, 26, 30, 10, 44
Answer: Mean = 27.2, Mode = 26, Median = 26, Range = 34