Keystones — Lintel
Five GCSE retrieval questions · 21 April 2026 · mathsvault.uk/keystones
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1. Number Multiplying in standard form
Calculate: 2.3 × 104 × 1.9 × 104
Answer: 4.37 × 108 -
2. Algebra Solving monic quadratics
Solve: x² - 13x + 42 = 0
Answer: x = -6 or x = -7 -
3. Geometry SOHCAHTOA — missing angle
Opposite = 11cm, adjacent = 11cm. Calculate the angle
Answer: 45° -
4. Ratio Reverse percentages
After a 27% decrease, a value is 140.89. What was the original?
Answer: 193 -
5. Statistics Range
Calculate the range of: 54, 75, 64, 48, 36, 71
Answer: 39