Keystones — Lintel
Five GCSE retrieval questions · 4 November 2025 · mathsvault.uk/keystones
-
1. Number Converting to standard form
50000000
Answer: 5 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² + x - 30
Answer: (x + 6)(x - 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 20cm, angle = 55°. Find opposite
Answer: 28.6cm -
4. Ratio Mixed ratio problems
In ratio 4:2:2, what fraction is the second part?
Answer: 2⁄8 -
5. Statistics Mean
The mean of 6 numbers is 36. If 5 of them are 42, 23, 35, 28, 35, what is the missing number?
Answer: 53