14.4 Does your answer make sense?

1. Is your answer about the size you expected? If you were finding the volume of a cube with sides 1.57 m long, you would expect the answer to be between 1 m³ (1 m 1 m 1 m) and 8 m³ (2 m 2 m 2 m). If your answer was 3 870 m³, you would know that you had made a mistake.
2. If you followed the advice in point 3 of Section 14.3 ‘Taking care with units’, the units of your answer should be consistent with any equation that you have used. If you were trying to find a speed (correct SI units m s^-1) and your answer had units of m³, you would know that something had gone wrong.
3. These checks won’t guarantee that your answer is correct, but they will frequently highlight when mistakes have been made.