Keystones — Lintel
Five GCSE retrieval questions · 23 April 2026 · mathsvault.uk/keystones
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1. Number Multiplying in standard form
Calculate: 8 × 104 × 6.2 × 105
Answer: 4.96 × 1010 -
2. Algebra Solving monic quadratics
Solve: x² -4x - 21 = 0
Answer: x = 7 or x = -3 -
3. Geometry SOHCAHTOA — missing angle
Opposite = 20cm, adjacent = 13cm. Calculate the angle
Answer: 57° -
4. Ratio Reverse percentages
After a 24% decrease, a value is 286.52. What was the original?
Answer: 377 -
5. Statistics Range
Find the range of: -18, 6, 8, -23, 34
Answer: 57