← Computer Science syllabus

EnglandComputer Science

Topic 1: Computational thinking

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do we write algorithms using sequence, selection and repetition, with variables, constants and data structures?

Follow and write algorithms (flowcharts, pseudocode, program code) that use sequence, selection, repetition (count-controlled, condition-controlled) and iteration with input, processing and output, and that use variables, constants and one- and two-dimensional data structures (strings, records, arrays).
A focused answer to Edexcel GCSE Computer Science 1.2.1 and 1.2.2, covering writing and following algorithms with sequence, selection and repetition, input-process-output, and variables, constants, strings, records and arrays.
9 min answer →

How do decomposition and abstraction make a hard problem solvable, and why do we split a program into subprograms?

Understand the benefit of using decomposition and abstraction to model aspects of the real world and to analyse, understand and solve problems, and understand the benefits of using subprograms.
A focused answer to Edexcel GCSE Computer Science 1.1.1 and 1.1.2, covering how decomposition and abstraction model the real world and help solve problems, and the benefits of using subprograms.
8 min answer →

What types of error occur in programs, how do the standard searching and sorting algorithms work, and how do we judge an algorithm's efficiency?

Understand syntax, logic and runtime errors and correct logic errors in algorithms; understand how the standard algorithms (bubble sort, merge sort, linear search, binary search) work; and use logical reasoning and test data to evaluate an algorithm's fitness for purpose and efficiency.
A focused answer to Edexcel GCSE Computer Science 1.2.5, 1.2.6 and 1.2.7, covering syntax, logic and runtime errors, the bubble sort, merge sort, linear search and binary search, and evaluating an algorithm's efficiency.
10 min answer →

Which arithmetic, relational and logical operators do algorithms use, and what does each one do?

Follow and write algorithms that use arithmetic operators (addition, subtraction, division, multiplication, modulus, integer division, exponentiation), relational operators (equal to, less than, greater than, not equal to, less than or equal to, greater than or equal to) and logical operators (AND, OR, NOT).
A focused answer to Edexcel GCSE Computer Science 1.2.3, covering the arithmetic operators including modulus and integer division, the relational operators, and the logical operators AND, OR and NOT in algorithms.
8 min answer →

How do you use a trace table to work out exactly what an algorithm does, step by step?

Determine the correct output of an algorithm for a given set of data, and use a trace table to determine what value a variable will hold at a given point in an algorithm.
A focused answer to Edexcel GCSE Computer Science 1.2.4, covering how to dry-run an algorithm, build a trace table row by row, and determine the value a variable holds and the output for given input data.
9 min answer →

How do you build and use a truth table for AND, OR and NOT with up to three inputs?

Apply logical operators (AND, OR, NOT) in truth tables with up to three inputs to solve problems.
A focused answer to Edexcel GCSE Computer Science 1.3.1, covering the AND, OR and NOT logical operators, how to build a truth table with up to three inputs, and how to use truth tables to solve problems.
8 min answer →