Keystones — Lintel
Five GCSE retrieval questions · 8 October 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
0.092
Answer: 9.2 × 10-2 -
2. Algebra Factorising monic quadratics
Factorise: x² - 8x + 16
Answer: (x - 4)(x - 4) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 35cm, angle = 34°. Find adjacent side
Answer: 29cm -
4. Ratio Mixed ratio problems
Divide 128 in the ratio 3:3:2
Answer: 48, 48 and 32 -
5. Statistics Mean
The mean of 4 numbers is 29. If 3 of them are 20, 30, 50, what is the missing number?
Answer: 16