Keystones — Lintel
Five GCSE retrieval questions · 2 November 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
0.026
Answer: 2.6 × 10-2 -
2. Algebra Factorising monic quadratics
Factorise: x² - 6x + 8
Answer: (x - 2)(x - 4) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 23cm, angle = 62°. Find adjacent side
Answer: 10.8cm -
4. Ratio Mixed ratio problems
Express the first part of 3:2 as a fraction in simplest form
Answer: 3⁄5 -
5. Statistics Mean
The mean of 5 numbers is 31. If 4 of them are 47, 28, 19, 21, what is the missing number?
Answer: 40