IGCSE Computer Science Paper 2 Definitions Worksheet: 7c Pseudocode and Flowcharts and 7d Standard Methods of Solution (Modules 254–264)
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Key terms
Write what each term means, in your own words.
1
Input, Process, Output
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DECLARE, INPUT, process, OUTPUT
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flowchart
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amend an algorithm
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REPEAT INPUT Mark UNTIL Mark >= 0 AND Mark <= 100
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command word
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UPPERCASE keywords
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DECLARE Score : INTEGER
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Total ← 0
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INPUT and OUTPUT
Answer Key
IGCSE Computer Science Paper 2 · Modules 254–264 · Student wording will vary for definitions
1Input, Process, Output — Plan before coding: read the problem, list what is input, what must be calculated or decided, and what is output. Then pick variables and spot repeats and decisions.
2DECLARE, INPUT, process, OUTPUT — To write an algorithm from a problem, DECLARE variables first, then INPUT, process with IF, CASE or a loop, then OUTPUT. Check each part against the problem and use the exam format.
3flowchart — A diagram that solves a problem using symbols for start, input, process, decision, output and stop, joined by arrows. Label each decision Yes or No and test every path to Stop.
4amend an algorithm — Find the part that must change for the new requirement, change only that part, then re-trace the algorithm to check the rest still works.
5REPEAT INPUT Mark UNTIL Mark >= 0 AND Mark <= 100 — A validation loop: it asks for INPUT again and again until the value passes the check (here a range check), so invalid data never enters the algorithm.
6command word — The exam word that tells you what to write: state the purpose, describe the processes, identify the error, suggest the correction, each in precise terms.
7UPPERCASE keywords — Cambridge pseudocode writes keywords like IF, FOR and WHILE in capitals and indents the lines inside each structure, so the code is easy to read.
8DECLARE Score : INTEGER — Creates a variable called Score with a stated data type. Types: INTEGER, REAL, STRING, CHAR, BOOLEAN. Pick a meaningful name.
9Total ← 0 — The ← arrow stores the value on its right in the variable on its left. Total ← 0 sets Total to 0. A new assignment replaces the old value. It is not the same as = used to compare.
10INPUT and OUTPUT — INPUT stores a value from the user in a variable, e.g. INPUT Number. OUTPUT shows a message or value on screen, e.g. OUTPUT "Total is ", Total. Prompt first so users know what to enter.