9709_m26_er — 2026 March Mathematics 9709 Examiner Report · Cambridge CAIE AS & A Level

Writing only the answer from a calculator without showing working

“No marks will be given for unsupported answers from a calculator. For quadratic equations, it would be necessary to show factorisation, use of the quadratic formula or completing the square.”— Paper 1, May/June 2023

How to fix: For quadratics: show factorisation, the quadratic formula with values substituted, or completing the square. For definite integrals: show the limit substitution. For cubic factorisation: show polynomial division or factor theorem steps. The answer alone earns zero — the method IS the mark.

Incomplete working in 'show that' questions

“To gain full marks in a 'show that' question it is necessary for candidates to show each step clearly and to be accurate in their algebra.”— Paper 1, March 2025

How to fix: In 'show that' questions: (1) Work TOWARDS the given answer, never FROM it. (2) Show every algebraic step — skipping lines loses marks. (3) If stuck, do NOT work backwards from the answer. (4) Confirm by stating the final result matches what was asked.

Premature rounding causing loss of accuracy marks

“When working with decimal numbers, candidates need to work to at least 4 significant figures to ensure accuracy when they round their answer to 3 significant figures.”— Paper 1, March 2025

How to fix: Keep at least 4 significant figures through all intermediate steps. Only round the FINAL answer to 3 sf. For exact answers (surds, fractions, pi), do not convert to decimals at all. In statistics, premature rounding of z-values leads to wrong probability areas.