GCSE Maths Command Words Explained

GCSE Maths command words are the instruction words in exam questions. Words like calculate, solve, simplify, factorise, estimate, show and prove tell you what kind of answer the examiner expects. Understanding them can help you avoid losing easy marks.

Exam tip: Before starting a question, underline the command word. It tells you whether you need a calculation, an explanation, algebraic working, a proof or a rounded estimate.

Why command words matter

Many GCSE Maths mistakes happen because students know the topic but answer the wrong question. For example, a question asking you to estimate is not asking for an exact calculator answer. A question asking you to show something is not asking you to simply write the final result.

Common mistake: A common mistake is rushing straight into calculation without reading the command word. Spend five seconds checking the instruction before you start.

Calculate

Calculate means work out a numerical answer. You usually need to show enough working so the examiner can see your method, especially on multi-mark questions.

Example

Calculate 18% of 250. A good method is 10% = 25, 5% = 12.5, 3% = 7.5, so 18% = 45.

Solve

Solve usually means find the value of an unknown. This is common in algebra questions. Your answer should make the equation true.

For example, in solving linear equations, you may need to collect like terms, use inverse operations and check your final value.

Simplify

Simplify means write an expression in a shorter or cleaner form without changing its value. This may involve collecting like terms, cancelling fractions or using index laws.

Simplifying is important in expanding brackets,fractions andindices.

Factorise

Factorise means put an expression into brackets. It is the reverse of expanding. For example, factorising 6x + 9 gives 3(2x + 3).

This skill is especially important for factorisingand quadratic equations.

Estimate

Estimate usually means round the numbers first, then calculate an approximate answer. The examiner wants to see sensible rounding and a rough answer, not exact calculator work.

Example

Estimate 49.8 × 19.6. Round to 50 × 20 = 1000.

Show that

Show that means the answer is already given, but you must prove how to reach it. You need clear working. Do not simply copy the answer from the question.

These questions often test method and reasoning, so each step should be written clearly.

Prove

Prove means give a logical mathematical argument. You may need algebra, angle facts, number properties or a sequence of clear statements.

Proof questions are often found in geometry, algebra and number topics. They are about explaining why something must always be true.

Video explanation

A short Worthing Maths Tutor video explanation for GCSE Maths command words explained can be embedded here later to improve student engagement and time on page.

Hence

Hence means use a previous result to answer the next part of the question. It is a hint that the earlier working is useful.

Describe or explain

Describe or explain means you need words, not just numbers. You may need to explain a pattern, justify a method or describe a relationship in a graph or diagram.

This is common in scatter graphs,probability andsequences.

How to practise command words

Related GCSE Maths guides

GCSE Maths command words FAQs

Do command words affect marks?

Yes. If you misunderstand the instruction, you may lose marks even if you know the topic.

Should I write working for calculate questions?

Usually yes, especially if the question is worth more than one mark. Working can earn method marks even if the final answer is wrong.

What should I do if I do not understand the command word?

Look at what the question gives you and what form the answer should take. Then choose the method that matches the instruction as closely as possible.

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