Technologies · Year 9

Active learning ideas

Functions and Parameters

Active learning turns abstract programming concepts into concrete experiences. When students define functions and pass parameters, they move from passive reading to active problem-solving, which builds deeper understanding of how modular code works in real programs. Collaborative activities let them test ideas, catch mistakes, and see immediate results, making parameters and scope less confusing and more meaningful.

• ACARA Content Descriptions
• AC9DT10P03

• 25–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Peer Teaching
• 30 min · Pairs

Pair Programming: Calculator Functions

Pairs define functions for add, subtract, multiply, and divide, each taking two parameters and returning a value. They call these in a main program for user-input calculations. Test with edge cases like division by zero.

Explain the purpose of parameters in making functions more versatile.

Facilitation Tip

During Pair Programming: Calculator Functions, circulate and ask pairs to verbally predict what will print before they run code, reinforcing that functions don’t run until called.

What to look for

Present students with a simple program that uses a function with a parameter. Ask them to: 1. Identify the function name. 2. Identify the parameter. 3. State what argument would be passed to make the function print 'Hello, World!'.

• Understand
• Apply
• Analyze
• Create
• Self-Management
• Relationship Skills

Activity 02

• Peer Teaching
• 45 min · Small Groups

Small Groups: Modular Story Generator

Groups create functions for random elements (adjective, noun, action) with parameters for themes. Combine into a main function that generates stories. Share and integrate functions across groups.

Differentiate between local and global variables within function scope.

Facilitation Tip

For the Modular Story Generator, provide a starter script with global variables so students can see how messy it gets without local scope, making the need for isolation clear.

What to look for

On an index card, ask students to write: 1. One reason why using functions makes code easier to manage. 2. An example of a variable that would have local scope and one that would have global scope in a simple calculator program.

• Understand
• Apply
• Analyze
• Create
• Self-Management
• Relationship Skills

Activity 03

• Peer Teaching
• 50 min · Whole Class

Whole Class: Function Chain Challenge

Class contributes functions to a shared program, like a simple adventure game. Each adds one function with parameters; run and debug collectively via projector.

Construct a program using multiple functions to perform a complex task.

Facilitation Tip

In the Function Chain Challenge, insist students write return statements first before coding logic, preventing the habit of ignoring returns.

What to look for

Pose the question: 'Imagine you are building a program to manage a library. What are two tasks you could create as separate functions, and what parameters might each function need?' Facilitate a brief class discussion on their ideas.

• Understand
• Apply
• Analyze
• Create
• Self-Management
• Relationship Skills

Activity 04

• Peer Teaching
• 25 min · Individual

Individual: Refactor Race

Students receive linear code for data analysis. Individually break it into functions with parameters and returns, then time improvements in efficiency.

Explain the purpose of parameters in making functions more versatile.

Facilitation Tip

During Refactor Race, give a messy code snippet and ask students to group related lines into functions, modeling how parameters improve adaptability.

What to look for

Present students with a simple program that uses a function with a parameter. Ask them to: 1. Identify the function name. 2. Identify the parameter. 3. State what argument would be passed to make the function print 'Hello, World!'.

• Understand
• Apply
• Analyze
• Create
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Teach functions and parameters through a cycle of definition, call, and reflection. Start with a worked example that fails until parameters are added, so students feel the pain of inflexible code. Use live coding to model debugging when functions aren’t called or returns are missing. Research shows students grasp scope best when they physically separate variables into different colored sections on the board or in comments.

By the end of these activities, students should confidently define functions with parameters, call them correctly, and explain why local scope matters. They will use returns to chain functions together and debug programs where definitions and calls don’t match. You’ll notice clearer code structure and fewer scope-related errors in their work.

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Watch Out for These Misconceptions

• During Pair Programming: Calculator Functions, watch for students who assume defining a function like add(a, b) means the program will automatically calculate answers.

  Set a timer for five minutes where pairs must write down when the function will execute and when it won’t, then verify by running the code. Ask them to circle the actual call statement to reinforce that definitions alone do nothing.

• During Modular Story Generator, watch for students who believe changing a parameter inside a function alters the original variable outside it.

  Ask each group to trace a story variable through two functions using colored pencils, one color for the original and another for the parameter. Have them hold up their traces when they present, highlighting where values diverge.

• During Function Chain Challenge, watch for students who omit return statements or treat them as optional.

  Display a sample chain on the board and physically cross out every return statement with a red marker. Then ask students to rewrite the program so the chain works, forcing them to value returns for continuity.

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Methods used in this brief

• Peer Teaching