OxfordAQA IGCSE Computer Science: Programming Fundamentals — Practice Questions (9210)

These are original questions written for Marlbridge, in the style and at the standard of the examination. They are not reproduced past-paper questions — examination boards hold copyright in their own papers. Use these alongside the official past papers available free from your board.

Related: Programming fundamentals study guide

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Section A

1. State the data type most appropriate for storing: (a) a person’s age (b) whether a light is on or off (c) a single letter grade. [3]

2. Evaluate: (a) 17 DIV 5 (b) 17 MOD 5. [2]

Section B

3. Identify the three “combining principles” of imperative programming named in the specification, and give one example construct for each. [6]

4. Trace through the following pseudocode and state the final value of Total.

Total <- 0
FOR i <- 1 TO 4
  IF i MOD 2 = 0 THEN
    Total <- Total + i
  ENDIF
ENDFOR

[4]

5. Write a compound condition using a relational and a Boolean operator that is true only when a variable Score is greater than 50 AND a variable LivesLeft is greater than 0. [3]

6. Explain why using meaningful identifier names (e.g. studentScore rather than x) is good programming practice. [3]

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Answers

(a) Integer [1]. (b) Boolean [1]. (c) Character (or string) [1].

2. (a) 17 DIV 5 = 3 [1]. (b) 17 MOD 5 = 2 [1].

3. Sequence — statements executed one after another in order, e.g. a series of assignment statements [1] [1]. Iteration — repeating a block of statements, e.g. a FOR or WHILE loop [1] [1]. Selection — choosing between different paths of execution, e.g. an IF...THEN...ELSE statement [1] [1].

4.

i = 1: 1 MOD 2 = 1 (not 0)          -- Total stays 0
i = 2: 2 MOD 2 = 0                  -- Total = 0 + 2 = 2
i = 3: 3 MOD 2 = 1 (not 0)          -- Total stays 2
i = 4: 4 MOD 2 = 0                  -- Total = 2 + 4 = 6

Final value of Total = 6

[1] mark for correctly tracing each iteration, [1] for correctly identifying which iterations satisfy the condition, [1] [1] for the correct final value with working shown.

5. Score > 50 AND LivesLeft > 0 [1] [1] [1] (1 mark for each correct relational operator used, 1 mark for correctly combining them with AND rather than OR).

6. Meaningful identifier names make the purpose of a variable clear from its name alone, without needing to trace through the code to work out what it stores [1] [1]. This makes code easier to read, debug and maintain, both for the original programmer returning to it later and for anyone else working with the code [1].

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Exam technique for this topic

Trace-table questions like Q4 are marked on showing working, not just the final value — set out each iteration of a loop on its own line, stating the condition being tested and whether it is true or false, since a correct final answer with no working shown may not earn full marks even though it demonstrates the right understanding. When identifying whether a loop should be definite (FOR) or indefinite (WHILE/REPEAT...UNTIL), ask whether the number of repetitions is known in advance — if it depends on a condition that could change unpredictably, an indefinite loop is required, not a FOR loop forced to approximate it. For compound conditions like Q5, always double-check whether the scenario needs AND (every part must be true) or OR (only one part needs to be true), since a condition using the wrong Boolean operator can silently produce working but incorrect code.

Worked example: writing an algorithm from a description

A question describes a simple program: read five numbers input by the user, and output whether each one is even or odd. A strong pseudocode answer combines all three constructs correctly:

FOR i <- 1 TO 5
  INPUT Number
  IF Number MOD 2 = 0 THEN
    OUTPUT "Even"
  ELSE
    OUTPUT "Odd"
  ENDIF
ENDFOR

This uses a definite loop (FOR, since exactly five numbers are known in advance), a MOD operation to test evenness (a number is even if it leaves no remainder when divided by 2), and a selection statement to output the correct result — practising this kind of translate-a-description-into-pseudocode exercise regularly, rather than only tracing pre-written code, builds the construction skill that longer algorithm-writing exam questions specifically assess.

Why pseudocode independence matters

Because 9210’s written exams always use OxfordAQA’s own pseudocode regardless of which language a candidate learned in the classroom, practising reading and writing in this specific pseudocode style — not just understanding the underlying logic in a familiar language like Python — is essential exam preparation. A candidate fluent in Python but unfamiliar with the exact pseudocode conventions used in this specification (for example, <- for assignment, or ENDIF/ENDFOR closing keywords) risks losing time or making translation errors under exam pressure, even when their underlying programming understanding is otherwise strong.

Where marks are usually lost

• Confusing DIV and MOD, or giving only one when a question asks for both the quotient and the remainder.
• Writing a definite loop (FOR) where the number of repetitions is not actually known in advance.
• Tracing a loop without showing each iteration’s working, losing method marks even with a correct final answer.
• Treating AND and OR as interchangeable, when they produce different results whenever the two conditions being combined disagree.