Skip to content
Oak National Academy
Oak National Academy
Teachers
Pupils
icon-background-square
New
New
Year 10
AQA

Tracing algorithms

I can use trace tables to test the logic of an algorithm.

Download all resources
arrow-right
Share activities with pupils
arrow-right
icon-background-square
New
New
Year 10
AQA

Tracing algorithms

I can use trace tables to test the logic of an algorithm.

Download all resources
arrow-right
Share activities with pupils
arrow-right
warning

These resources will be removed by end of Summer Term 2025.

Switch to our new teaching resources now - designed by teachers and leading subject experts, and tested in classrooms.
View new resources
arrow-right

Lesson details

Key learning points

  1. Trace tables can be used to walkthrough and understand the logic of an algorithm.
  2. Trace tables can be used to help find logical errors in algorithms.

Keywords

  • Trace table - a tool used to track the values of variables and the flow of execution in an algorithm or program, step by step

  • Error - a mistake or unexpected behaviour in a program that prevents it from working correctly

  • Modulo - an operation that gives you the remainder when one number is divided by another

Common misconception

Using trace tables guarantees correct logic and code.

Trace tables can be subject to human error and can be impractical to use for complex algorithms.


To help you plan your year 10 computer science lesson on: Tracing algorithms, download all teaching resources for free and adapt to suit your pupils' needs...

Initially, pupils can struggle to keep track of variable changes in trace tables. Model the completion of trace tables slowly by narrating the changes as they happen.
speech-bubble
Teacher tip
equipment-required

Equipment

copyright

Licence

This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

Skip lesson video

Loading...

Starter quiz

Download starter quiz

6 Questions

Q1.
What is a set of step-by-step instructions to solve a problem called?
Correct Answer: algorithm, an algorithm, algorithms
Q2.
Why is it helpful to develop an algorithm’s logic before coding?
Correct answer: It makes problem solving easier.
It wastes time.
It creates unnecessary steps.
It’s only useful for flowcharts.
Q3.
What is a diagram that represents logic or data (or similar alternatives)?
Correct Answer: flowchart, flow chart
Q4.
What does decomposition involve?
ignoring the problem entirely
Correct answer: breaking down problems into smaller subproblems
writing a program directly
creating a flowchart
Q5.
What is abstraction in computational thinking?
focusing on irrelevant details
writing a program in plain language
ignoring the important parts of a problem
Correct answer: focusing on the important parts and ignoring irrelevant details
Q6.
What is a way to express an algorithm in plain language (or similar alternatives)?
Correct Answer: pseudocode, pseudo code

Exit quiz

Download exit quiz

6 Questions

Q1.
Match the terms with their definitions.
Correct Answer:trace table,a tool to track variable values and execution flow
tick

a tool to track variable values and execution flow

Correct Answer:error,a mistake in a program that prevents it from working correctly
tick

a mistake in a program that prevents it from working correctly

Correct Answer:modulo,an operation that gives the remainder when dividing two numbers
tick

an operation that gives the remainder when dividing two numbers

Correct Answer:human error,mistakes made by people when creating trace tables
tick

mistakes made by people when creating trace tables

Correct Answer:execution,the process of running an algorithm or program
tick

the process of running an algorithm or program

Q2.
What is a trace table used for?
to draw flowcharts
to write pseudocode
Correct answer: to track variable values in a program
to translate algorithms into code
Q3.
What is a common limitation of trace tables?
they are always correct
Correct answer: they can be subject to human error
they only work for pseudocode
they cannot track variable values
Q4.
What is the result of 10%3?
Correct Answer: 1, one
Q5.
Arrange these steps into the correct order for creating a trace table.
1 - Write the algorithm.
2 - Identify the variables in the algorithm.
3 - Track the values of variables step by step.
4 - Analyse the results to find errors.
Q6.
Why might trace tables be impractical for complex algorithms?
they are too simple to use
they cannot track variables
they only work for pseudocode
Correct answer: they can become too large and difficult to manage