From lost method marks to wrong calculator mode, here are the most common GCSE Maths mistakes students make — and exactly how to avoid them.
GCSE mark schemes award method marks independently of the final answer. Students who work in their head or on a calculator without showing steps forfeit these marks entirely. For questions worth 3 or more marks, showing every step can score more marks than getting the final answer right.
A calculator in "radians" mode will give wrong answers for GCSE trigonometry questions, which use degrees. Always check your calculator mode at the start of each paper.
Premature rounding is heavily penalised. Carry at least 4 decimal places in intermediate steps for geometry and trigonometry questions, and only round at the final step.
Expanding negative brackets is the most common source of sign errors. Remember: −3(x − 4) = −3x + 12, not −3x − 12. Always use brackets when substituting negative values into formulas.
Many mark schemes deduct a mark for missing units. Length, area, volume, speed, and time all require units on the final answer.
The GCSE Maths exam allows approximately 1 minute per mark. If you are stuck after a few minutes, move on, mark the question, and return if time allows. Students who spend 20 minutes on one question and run out of time on later questions leave marks on the table.
Exam Ladder turns every tip in this article into action — adaptive questions, spaced repetition, and AI explanations built in.
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