Keystones — Lintel
Five GCSE retrieval questions · 14 October 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
0.00031
Answer: 3.1 × 10-4 -
2. Algebra Factorising monic quadratics
Factorise: x² + x - 12
Answer: (x + 4)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 17cm, angle = 57°. Find opposite
Answer: 26.2cm -
4. Ratio Mixed ratio problems
Simplify the ratio 7m:700cm
Answer: 1:100 -
5. Statistics Mean
The mean of 6 numbers is 31. If 5 of them are 25, 39, 38, 42, 38, what is the missing number?
Answer: 4