Keystones — Lintel
Five GCSE retrieval questions · 26 January 2026 · mathsvault.uk/keystones
-
1. Number Error intervals
A value is 94.5 (to dp). State the error interval
Answer: 94.45 ≤ x < 94.55 -
2. Algebra Expanding two brackets
Expand: (x - 5)(x - 3)
Answer: x² - 8x + 15 -
3. Geometry Area of a circle
Calculate the area of a circle with diameter 15cm
Answer: 176.71cm² -
4. Ratio One amount as a percentage of another
48 out of 91 students passed. What percentage passed?
Answer: 52.7% -
5. Statistics Averages and range
Find the mean, median and range of: 76, 22, 78, 92, 44, 17, 94, 79, 63
Answer: Mean = 62.8, Median = 76, Range = 77