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Lesson 5 of 8
  • Year 10
  • OCR

Variables and constants in programs

I can apply appropriate naming conventions and explain the differences between variables and constants.

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View unit
Lesson 5 of 8
New
New
  • Year 10
  • OCR

Variables and constants in programs

I can apply appropriate naming conventions and explain the differences between variables and constants.

Download all

Lesson details

Key learning points

  1. Naming conventions improve code readability and maintainability.
  2. A variable is a named piece of data stored in a computer’s memory.
  3. A variable can be accessed and changed by a computer program.
  4. Variables must be declared and assigned values in a program.
  5. Constants hold fixed values that do not change throughout the running of the program.

Keywords

  • Variable - a named piece of data stored in a computer’s memory which can be accessed and changed by a computer program

  • Declaration - the process of stating the name of a variable or constant and defining its data type

  • Initialisation - assigning a starting value to a variable to let the compiler know that a memory location is required

  • Constant - a value that cannot be changed during the execution of a program

Common misconception

You can define a constant in any programming language.

Python does not have constants. But if you want a value to be treated as a constant, it's a common naming convention for the identifier to be written in capital letters.


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

Demonstrate the use of constants in a programming language that supports them. Pupils should see how constants cannot be changed once initially assigned.
Teacher tip

Equipment

Pupils will need access to a device that can edit and run Python programs. Examples in this lesson use the RPF Code Editor https://oak.link/python-editor

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

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Prior knowledge starter quiz

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6 Questions

Q1.
What does IDE stand for?

Intelligent Debugging Engine
Internal Data Exchange
Interactive Design Editor
Correct answer: Integrated Development Environment

Q2.
Match the terms to their definitions:

Correct Answer:input,data sent to a program to be processed

data sent to a program to be processed

Correct Answer:output,information produced by a computer system

information produced by a computer system

Correct Answer:IDE,an application that facilitates the writing and running of programs

an application that facilitates the writing and running of programs

Q3.
What feature uses colours to distinguish code elements?

Correct Answer: Syntax highlighting

Q4.
What Python function is used to receive data from the user during program execution?

Correct Answer: input()

Q5.
What Python function is used to display output to the user during program execution?

Correct Answer: print()

Q6.
What is the primary purpose of output devices?

to send data to the computer
Correct answer: to display or produce information from the computer
to store data
to process data

Assessment exit quiz

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6 Questions

Q1.
What is a variable?

a piece of data that cannot be changed
a type of constant used in programs
a value that always remains fixed
Correct answer: a named piece of data stored in memory that can be accessed and changed

Q2.
What is a constant?

Correct answer: a value that cannot be changed during the execution of a program
a type of variable
a naming convention for variables
a temporary value stored in a program

Q3.
What is the purpose of naming conventions?

to make the code run faster
to reduce memory usage
Correct answer: to improve code readability and maintainability
to avoid using variables

Q4.
What is initialisation in programming?

declaring a variable as a specific data type
Correct answer: assigning an initial value to a variable
assigning a value to a constant
using a variable without declaring it

Q5.
Is it possible to define a constant in Python?

Yes, Python has built-in constants.
Yes, constants can be declared using a specific keyword.
Correct answer: No, Python does not allow the use of constants.

Q6.
What variable name would be commonly used to store a first name in Python?

Correct Answer: first_name