Keystones — Lintel
Five GCSE retrieval questions · 17 November 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
91000000
Answer: 9.1 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² - 8x + 16
Answer: (x - 4)(x - 4) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 37cm, angle = 63°. Find adjacent side
Answer: 16.8cm -
4. Ratio Mixed ratio problems
Express the first part of 6:4 as a fraction in simplest form
Answer: 3⁄5 -
5. Statistics Mean
The mean of 6 numbers is 27. If 5 of them are 39, 39, 36, 45, 30, what is the missing number?
Answer: -27