Command Words

Estimate

Round every value to 1 significant figure, then calculate. Do not use the exact values.

Definition

In maths exams, "estimate" almost always means: round everything to 1 significant figure and then calculate. Using the exact numbers loses every mark on the question, even if your final answer is close.

Example

Estimate 5.84 × 19.7. Round to 1 s.f.: 6 × 20 = 120. Answer: 120.

Common confusion

Students round to 2 or 3 s.f. — losing marks because the mark scheme demands 1 s.f. for an estimate.

Used in these topics

Bounds and error intervals →

Related terms

Calculate

Work out an exact value using the given numbers. Show your method.

Work out

Show how you reached the answer. Synonymous with "calculate" but emphasises the working.

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