Keystones — Lintel
Five GCSE retrieval questions · 24 October 2026 · mathsvault.uk/keystones
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1. Number Converting to standard form
95000
Answer: 9.5 × 104 -
2. Algebra Factorising monic quadratics
Factorise: x² - 8x + 15
Answer: (x - 5)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 36cm, angle = 36°. Find adjacent side
Answer: 29.cm -
4. Ratio Mixed ratio problems
In ratio 1:4:2, what fraction is the second part?
Answer: 4⁄7 -
5. Statistics Mean
The mean of 5 numbers is 30. If 4 of them are 39, 22, 49, 25, what is the missing number?
Answer: 15