Functions in programs
Lesson details
Learning outcome
I can create a program that uses a function to return values.
Key learning points
- A function is a named block of code that is called to perform a task and will return a value.
- A return value is a value that is returned to the calling program.
- Arguments are values provided to a subprogram at the time it is called.
- Subprogram parameters are values used by the subprogram that are passed from the arguments when it is called.
Keywords
Function - a subprogram that returns a value
Return value - a value that is returned by a function
Parameter - used in a subprogram to allow values to be passed into them
Argument - values held in the brackets of a subprogram call, which are passed into a subprogram via the parameters
Common misconception
When a function returns a value it can be used throughout the program that called it.
The return value needs to be stored if it is to be used later in the program that calls it.
Teacher tip
Draw parallels to functions that pupils have already used such as input(). If the text entered is not stored in a varibale, it cannot be used. Ask pupils to suggest other such examples.
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
Lesson video
Loading...
Prior knowledge starter quiz
6 Questions
Q1.A is a section of code that performs a specific task.
Q2.What is the correct syntax for defining a procedure in Python?
Q3.What is the difference between a procedure and a function?
Q4.Match the terms to the definitions.
a subprogram that executes a block but does not return a value
a subprogram that returns a value
a value that is returned by a function
an expression that passes control and arguments to a subprogram
Q5.The values passed to a procedure when it is called are called .
Q6.The variables defined inside a procedure are called .
Assessment exit quiz
6 Questions
Q1.What is the primary purpose of a function in programming?
Q2.Which keyword is used to define a function in Python?
Q3.What are the values passed to a function called?
Q4.Match the following terms and definitions.
a named block of code that performs a task and returns a value
values used by the function that are passed to it when it is called
a value that is returned by a function
values provided to a function at the time it is called
Q5.A function can have __________ parameters.
Q6.The keyword used to send a value back from a function is .
To help you plan your 10 computer science lesson on: Functions in programs, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 computer science lesson on: Functions in programs, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 computer science lessons from the Programming: subprograms unit, dive into the full secondary computer science curriculum, or learn more about lesson planning.