Keystones — Lintel
Five GCSE retrieval questions · 20 November 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
150000
Answer: 1.5 × 105 -
2. Algebra Factorising monic quadratics
Factorise: x² + 2x - 8
Answer: (x + 4)(x - 2) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 40cm, angle = 26°. Find adjacent side
Answer: 36cm -
4. Ratio Mixed ratio problems
Divide 55 in the ratio 3:1:1
Answer: 33, 11 and 11 -
5. Statistics Mean
The mean of 5 numbers is 27. If 4 of them are 42, 18, 18, 50, what is the missing number?
Answer: 7