Top 200 Vocabulary Word List for Cambridge International AS & A Level | Must Know Words for Common Examination Instructions

The 200-word examination instruction list

Cambridge International AS & A Level command words tell you how to present the knowledge you have. Show that calls for a chain of working to a stated result. In an investigation, suggest an improvement calls for a change that addresses a specific weakness. This list uses Mathematics 9709 and Biology 9700 to make those differences concrete.

The numbered bank combines commands, task phrases and supporting terms. Use the examples and official sources below to see how an instruction changes the answer you give.

Exam requirements · Worked examples · Fencing Method

Pure mathematics, mechanics and statistics

No.	Instruction or term	What it asks you to do
1	Find in terms of x	Give an expression involving x rather than a decimal obtained by choosing a value for x.
2	Obtain	Work through the required steps to reach the result specified.
3	Show an equation has a root	Use a valid argument, such as a sign change with continuity on the interval.
4	Find the exact value	Retain radicals, fractions, logarithms or π in exact form where appropriate.
5	Give your answer to three significant figures	Round the final value to three meaningful digits unless another instruction applies.
6	Use radians	Express the angle in the required unit and check the calculator mode if using one.
7	Find all solutions	Include every solution in the stated domain or interval.
8	Within the interval	Keep solutions inside the stated endpoints, respecting whether the endpoints are included.
9	Differentiate implicitly	Apply differentiation to the given relation without first isolating the dependent variable.
10	Stationary point	Find where the derivative is zero or identify the requested point from the information given.
11	Determine the nature	Decide whether the stationary point is a maximum, minimum or other case using evidence.
12	Increasing function	Use the domain and the relevant behaviour of the function, such as a positive derivative.
13	Integrate	Obtain the required antiderivative or definite integral.
14	Constant of integration	Include an arbitrary constant in an indefinite result and determine it when conditions allow.
15	Limits of integration	Use the specified lower and upper endpoints in a definite integral.
16	Find the area	Find a non-negative area and account for changes in sign or intersecting curves.
17	Initial condition	Use the value specified at the starting point to determine the model or its constant.
18	Set up an equation	Translate the given conditions into a mathematical relationship.
19	Solve the differential equation	Find the relationship satisfying the equation and any stated initial conditions.
20	Express in partial fractions	Rewrite the rational expression as simpler fractions with the appropriate denominators.
21	Expand in ascending powers	Write terms from the lowest relevant power upwards.
22	Up to and including	Include the last specified term or value.
23	Coefficient of	Find the multiplier of the specified term or power.
24	Resultant	Find the overall effect of the stated vectors or forces.
25	Resolve	Split a vector or force into components in the directions required.
26	Take moments	Use the turning effects about the specified point or a suitable pivot.
27	In equilibrium	Set the relevant resultant force or turning effect to zero.
28	Model as a particle	Represent the object by its mass at a point where the stated modelling assumptions apply.
29	Smooth surface	Use the model’s assumption of negligible friction when appropriate.
30	Light string	Treat the string’s mass as negligible in the stated model.

Statistics, Biology and paper directions

No.	Instruction or term	What it asks you to do
31	State an assumption	Name a modelling condition that the solution relies on.
32	Interpret the parameter	Connect a symbol or numerical coefficient to the quantity it represents.
33	Random variable	Identify the numerical outcome defined by the problem.
34	Probability distribution	Use or construct the probabilities associated with the possible outcomes.
35	Expected value	Find the probability-weighted mean under the stated model.
36	Given that	Restrict the calculation to the condition specified by the question.
37	Mutually exclusive	Check whether the events cannot occur together.
38	Independent events	Check whether learning that one event occurred changes the probability of the other.
39	Use a normal approximation	Apply the stated approximation and any correction appropriate to the task.
40	Continuity correction	Adjust a discrete boundary before applying a continuous approximation where required.
41	Null hypothesis	State the reference claim about the population parameter.
42	Alternative hypothesis	State the competing claim and check whether it specifies a direction.
43	Significance level	Use the stated threshold for making the test decision.
44	Critical region	Find the outcomes that would lead to rejection under the test rule.
45	Interpret the result in context	Name the relevant population, quantity or effect when explaining your conclusion.
46	Biological mechanism	Link the observation to the underlying process in the requested order.
47	Draw a plan diagram	Show the layout of tissue regions without adding individual cells unless required.
48	Use a calibrated scale	Convert the observed divisions to real dimensions with the given calibration.
49	Serial dilution	Prepare or calculate successive solutions using the stated dilution steps.
50	Test the hypothesis	Use the specified data or design to assess the predicted relationship.
51	Standardise	Apply the same method, condition or basis across comparisons.
52	Explain the effect on validity	Link the identified design feature to what the investigation can establish.
53	Further evidence	Identify a new observation that would help resolve the specific uncertainty.
54	Paper combination	Check the syllabus and school entry for the papers taken together.
55	Staged assessment	Check how eligible AS results may contribute to a later A Level entry under the relevant rules.

Extended answers, evidence and working

No.	Instruction or term	What it asks you to do
56	Compare and contrast	Address similarities and differences for the named items.
57	To what extent	Judge how far a claim holds and explain any important limits.
58	Show that	Use clear intermediate steps to derive a result already stated.
59	Show	Make the necessary working or reasoning visible.
60	Deduce	Use the information given to reach a logically supported result.
61	Prove	Establish a statement through a valid chain of reasoning.
62	Derive	Work from accepted relationships to obtain a new expression or result.
63	Verify	Test whether the proposed result meets the stated requirements.
64	Hence	Use the preceding result to answer the next part.
65	Hence or otherwise	Use the preceding result or choose another valid route.
66	Write down	Give a result recoverable directly from the information provided.
67	Draw	Provide a labelled and accurate representation where required.
68	Sketch	Show the essential shape or features with the required labels.
69	Plot	Mark points at their correct positions on the stated axes.
70	Annotate	Add short notes that explain specific features of a figure or text.
71	Comment	Give a focused judgment based on the information supplied.
72	Formulate	Express an idea, model or hypothesis in a clear and usable form.
73	Construct	Produce the representation or argument specified, with the required accuracy.
74	Examine	Investigate the features and relationships that matter to the question.
75	Explore	Investigate the material using relevant observations or approaches.
76	Critique	Appraise how well the claim or method works and where it falls short.
77	Account for	Give the reasons that explain the pattern or outcome.
78	Hypothesis	State a testable prediction about a relationship.
79	Research question	Specify the focused question that the investigation will answer.
80	Variable	Identify a quantity or feature that can change.
81	Independent variable	Identify the factor changed or selected as the input.
82	Dependent variable	Identify the outcome measured or modelled.
83	Controlled variable	Identify a factor kept constant to help isolate the tested relationship.
84	Control treatment	Identify a comparison condition used as a baseline.
85	Raw data	Use the measurements as originally collected.
86	Processed data	Use values calculated, combined or transformed from the original readings.
87	Uncertainty	State or interpret the estimated doubt associated with a measurement or value.
88	Absolute uncertainty	Express the estimated uncertainty in the same units as the quantity.
89	Percentage uncertainty	Express the uncertainty relative to the measured value as a percentage.
90	Error bars	Read the kind and size of spread or uncertainty identified in the legend.
91	Outlier	Identify an observation unusually far from the general pattern.
92	Anomalous result	Recognise a result inconsistent with the main pattern or expected relationship.
93	Reliability	Consider whether a result or method gives consistent findings.
94	Validity	Consider whether the evidence or method answers the intended question.
95	Precision	Consider the consistency or resolution of the stated measurements.
96	Accuracy	Consider closeness to a suitable reference value.
97	Resolution	Identify the smallest change that the device or scale can display.
98	Repeatability	Consider agreement when the same method is repeated under the same conditions.
99	Reproducibility	Consider whether results agree when the method is repeated under changed conditions.
100	Limitations	Identify specific boundaries on the conclusions that the method can support.
101	Strengths	Explain features that make the evidence or method fit the purpose.
102	Improvement	Connect a specific modification to the problem it would address.
103	Correlation	Describe how variables vary together within the data.
104	Causation	Explain how one factor produces a change in another when evidence supports it.
105	Confounding factor	Identify a factor that could contribute to the apparent relationship.
106	Sample size	Check how many observations, individuals or trials contribute to the result.
107	Representative sample	Check whether the selected cases reflect the population of interest.
108	Random sampling	Use a selection process that assigns known selection chances by chance.
109	Model	Use a simplified mathematical or conceptual representation to address the task.
110	Parameter	Identify a quantity that sets a feature of the model.
111	Domain	Give the set of allowed input values in the context.
112	Boundary condition	Identify a requirement at an endpoint or boundary.
113	Interpolate	Estimate within the range covered by the data.
114	Extrapolate	Estimate outside the observed range using an assumed pattern.
115	Fit	Judge how closely a model agrees with the data.
116	Residual	Find the observed value minus the model’s predicted value.
117	Rate of change	Find the change in one quantity per unit change in another.
118	Exact form	Retain the full mathematical value in the requested representation.
119	Approximation	Give a suitably rounded or estimated value.
120	In terms of	Use the specified quantity or symbol in the final expression.
121	Significant figures	Give the requested number of meaningful digits.
122	Decimal places	Give the requested number of digits to the right of the decimal point.
123	Deductive reasoning	Show how a conclusion follows from premises or prior results.
124	Counterexample	Give one valid case that disproves a general claim.
125	Counterclaim	Present a plausible position that challenges the claim.

Core words, sources and answer format

No.	Instruction or term	What it asks you to do
126	Recognise	Find a familiar feature in a new example.
127	Identify	Name or pick out the item the question specifies.
128	Select	Choose only the number of options requested.
129	Match	Pair each item with the option that corresponds to it.
130	Complete	Fill in what is missing while keeping the supplied structure.
131	Label	Attach the correct name to the indicated part.
132	Locate	Find the specified detail, point or region.
133	Indicate	Make the chosen feature or answer clear.
134	Record	Write the result in the space and form provided.
135	Answer	Respond directly to the question being asked.
136	Give	Supply the requested fact, example or result.
137	State	Express the required point directly and clearly.
138	Name	Supply the correct term, person or item.
139	List	Set out the requested items separately.
140	Define	Give the precise meaning used in the subject or question.
141	Describe	Report the relevant characteristics, events or pattern.
142	Outline	Give the main steps or points in brief.
143	Summarise	Select the central points and leave out minor details.
144	Explain	Connect the result to its cause, mechanism or reasoning.
145	Compare	Identify similarities and/or differences as the Cambridge question directs.
146	Contrast	Show how the items differ on a shared point of comparison.
147	Analyse	Break down the evidence and explain how its parts relate.
148	Interpret	Say what a statement, result or display means in context.
149	Infer	Use clues to reach a conclusion the material implies.
150	Predict	Use available evidence to say what is likely to happen.
151	Suggest	Offer a plausible answer suited to the information given.
152	Justify	Give evidence or reasoning that supports your answer.
153	Evaluate	Weigh relevant evidence or criteria before reaching a judgment.
154	Assess	Judge the extent, value or strength of something using evidence.
155	Discuss	Develop a structured response that considers the relevant issues.
156	Distinguish	Give the feature that lets the reader tell two things apart.
157	Support	Supply evidence that helps establish the claim.
158	Illustrate	Make an idea clear with a relevant example or diagram.
159	Demonstrate	Show how a fact, process or result can be established.
160	Determine	Work from the given information to establish an answer.
161	Calculate	Use numbers or other given information to work out a result.
162	Estimate	Find an approximate answer using the available clues.
163	Check	Test the answer against the original instruction or condition.
164	Arrange	Put items into the order or grouping requested.
165	Sequence	Put stages into a meaningful order.
166	Classify	Assign each item to a category using the stated rule.
167	Group	Put items with a shared feature together.
168	Order	Sort items by the criterion given in the prompt.
169	Omit	Leave out the indicated item or detail.
170	Include	Make sure the requested part appears in the response.
171	Exclude	Keep the named item or category outside your answer.
172	Refer to	Use the specified passage, figure or notes when responding.
173	Based on	Ground the answer in the material named in the question.
174	According to	Use what the specified source says.
175	In context	Use the meaning that fits this passage or situation.
176	Most likely	Choose the conclusion with the strongest support among the options.
177	Best supported	Prefer the conclusion backed most directly by the evidence.
178	Explicit	Stated directly in the source.
179	Implicit	Suggested by the source and recoverable from clues.
180	Evidence	A fact, detail or observation that supports a claim.
181	Claim	An assertion that can be tested against evidence or reasoning.
182	Example	A particular case used to make a general idea clear.
183	Conclusion	The result reached after considering the reasoning or evidence.
184	Assumption	A premise taken as given for the purpose of the question.
185	Condition	A requirement that must be satisfied.
186	Constraint	A restriction that shapes the possible answers.
187	Criterion	A standard used to choose or judge an answer.
188	Context	The surrounding information that helps determine meaning.
189	Source	The particular text, figure, notes or data supplied for use.
190	Passage	A stretch of text provided for reading and answering questions.
191	Statement	A complete assertion to examine or respond to.
192	Option	One of the choices the question offers.
193	Section	A group of questions or tasks within a test.
194	Figure	A numbered graph, image or diagram referred to in the task.
195	Table	Information arranged in rows and columns.
196	Graph	A visual display of data or a mathematical relationship.
197	Diagram	A drawing showing features, structure or relationships.
198	Trend	The broad direction or pattern over a range.
199	Pattern	A regularity visible across observations or examples.
200	Scale	The intervals or measurement relationship used in a display.

What the examination requires

Start with your syllabus and paper combination

Cambridge publishes a general command-word glossary, while subject syllabuses can define terms for their own questions. Use the syllabus for your examination year. Write down the subject code, component numbers and entry route before selecting a practice paper. Cambridge International AS & A Level and Singapore–Cambridge GCE A-Level have separate syllabuses and assessment rules.

Mathematics 9709 for examination in 2026 and 2027

AS candidates take two components. A Level candidates take four. At A Level, candidates take Papers 1 and 3, plus either Papers 4 and 5 or Papers 5 and 6. The AS Pure Mathematics-only combination of Papers 1 and 2 cannot be carried forward to complete the A Level. Check the route with your centre, then practise the instructions and allowed materials for those exact papers.

Biology 9700 for examination in 2025–2027

AS candidates take Papers 1, 2 and 3. The full A Level assessment comprises Papers 1 to 5, with staged and single-series routes described in the syllabus. Paper 3 assesses advanced practical skills through practical work. Paper 5 is a written paper on planning, analysis and evaluation. Practise identifying variables, representing data and explaining what a proposed change improves.

Check the final output

The word at the start may tell you to calculate, derive or explain. A phrase later in the question can still determine which inputs, interval, units or precision count. Keep the earlier result visible when a later part says hence. When the task involves data, check that your conclusion refers to the stated population, sample or biological system.

• Read the complete prompt and mark the required action.
• Check the source, data or part of the question the action applies to.
• Give the requested response in the stated form.

Worked examples of common examination instructions

These original practice examples show the work each instruction calls for.

Show that, then use the result

An original practice question defines f(x) = x² − 6x + 13 and asks you to show that f(x) = (x − 3)² + 4. Expand (x − 3)² + 4 or complete the square on the original expression, keeping the equality clear. Hence find the minimum. The square is at least zero and equals zero when x = 3, so the minimum is 4. Showing the identity and using it are separate tasks.

Keep the reference population in a probability question

In a group of 60 students, 24 commute by train. Of those 24, six also cycle for part of the journey. Given that a student commutes by train, find the probability that they also cycle. The reference group contains 24 students, so the answer is 6/24 = 1/4. Dividing by 60 would answer a different question about the full group.

Describe data, then evaluate a proposed conclusion

Two treatments produced mean increases of 1.8 cm and 2.6 cm in root length. The second mean was 0.8 cm higher. If each treatment was applied to plants kept in a different room, a room difference could contribute to the result. Comparing the numbers addresses describe. Explaining how the design limits a causal conclusion addresses evaluate.

Link a practical improvement to its purpose

Suppose students read a scale from an angle in a trial that measures liquid volume. Read the scale at eye level to reduce parallax. Taking more readings can reveal random variation, while eye-level reading addresses the particular measurement problem identified. Name the problem and say what the proposed change achieves.

Use the Fencing Method to practise instructions

Start with one accurate sentence. Add a precise detail, then add the link the instruction asks for. Use a fresh example at the end to see whether you can perform the same action without relying on the original wording.

1. The second mean was higher.
2. The second treatment’s mean increase in root length was 0.8 cm higher.
3. The second treatment’s mean increase was 0.8 cm higher, but the groups were kept in different rooms.
4. Apply evaluate to another investigation. Name a design feature, state what it might affect and explain how that limits the conclusion.

Read the eduKate Fencing Method for Vocabulary.

Practise and check your answers

Switch between the Mathematics and Biology routes

For Mathematics, cover the last line of a completed problem and use the command to reconstruct the output. For Biology, cover your conclusion and rebuild it from the exact figures and design details. In both subjects, practise finding the moment at which the task stops asking for a result and begins asking for a reason.

Mark the dependency between subparts

When part (b) refers to an earlier result, write the exact result you are carrying forward before substituting it. Check whether the new part requests a different variable, interval or unit. After a specimen, compare the steps you showed with the method points and the paper’s directions.

Practice 1. Find all solutions to sin x = 1/2 on 0° ≤ x ≤ 360°.

Give 30° and 150°. The interval and all tell you to check both relevant quadrants.

Practice 2. A study changes temperature and records gas volume after five minutes. Which variable should appear on each axis?

In a standard graph of the outcome against the input, place temperature on the horizontal axis and gas volume on the vertical axis. Include the given units.

Practice 3. A Paper 5 practice response says only ‘repeat it’ as an improvement. How can you make it usable?

Specify what to repeat under each condition and what to do with the new readings. If the limitation is a systematic measurement bias, propose a change that addresses that bias.

Practice 4. A question gives x in radians and requests the nearest degree. When should you convert?

Carry out the requested mathematical work in the appropriate mode, then convert the final angle and round it to the nearest degree.

Frequently asked questions

Which guide should I use if my subject is neither Mathematics nor Biology?

Use the glossary and paper instructions for your subject code. Use this list to practise recognising the job a verb asks you to do.

Can I use a different method for a question that says hence?

Use the preceding result when the instruction says hence. If it says hence or otherwise, another valid route may meet the task.

What if I have finished only the AS Pure Mathematics-only route?

Check the 9709 syllabus and speak with your examination centre about the entry route. Papers 1 and 2 as an AS combination cannot be carried forward to complete the A Level.

Official exam sources and next reading

• Cambridge International command words
• Mathematics 9709 syllabus for 2026–2027
• Biology 9700 syllabus for 2025–2027

Related guide in this series · Cambridge IGCSE command words

Read eduKateSG’s 200-word vocabulary guide for more ways to group and practise vocabulary.

Back to the 200-word list · Back to contents