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Omitting or forgetting units on final numerical answers
“In some calculation questions the final mark was not awarded due to a missing unit. This seemed to be more prevalent in this years' examination.”— 9PH0 Paper 3, June 2023
How to fix: After every calculation, check: magnitude written? unit written? For SI-prefixed answers, write the unit explicitly (e.g. 2.4 × 10⁻³ kg, not just 2.4 × 10⁻³). Note that 'show that' questions are the only exceptions where final units are not penalised — on all other calculation questions a missing unit costs the answer mark.