Computing · Year 3

Active learning ideas

Introduction to Block Coding

Active learning works well for debugging because it turns abstract errors into visible problems students can solve together. Students remember debugging strategies better when they experience the frustration of a bug and then find the fix themselves, rather than just hearing about it.

• National Curriculum Attainment Targets
• KS2: Computing - Programming
• KS2: Computing - Logical Reasoning

• 20–30 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Simulation Game
• 30 min · Pairs

Simulation Game: Bug Hunt

The teacher provides a 'broken' program where a sprite doesn't do what it's supposed to. In pairs, students must use a 'detective checklist' to test each block one by one until they find the 'culprit'.

Explain how dragging and dropping blocks creates instructions for a computer.

Facilitation Tip

During Bug Hunt, circulate with a checklist of common bugs to help students notice patterns in their errors.

What to look for

Provide students with a pre-written simple sequence of 3-4 code blocks. Ask them to draw what the sprite will do, step-by-step, and write one sentence explaining why it moves that way.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 02

• Role Play
• 25 min · Pairs

Role Play: The Debugging Doctor

Students take turns being the 'Doctor' and the 'Patient' (the programmer). The Patient explains what is 'hurting' in their code, and the Doctor asks logical questions to help diagnose the bug without just fixing it for them.

Compare the different types of blocks available in a programming environment.

Facilitation Tip

In The Debugging Doctor, model how to ask questions like, ‘What did you expect this block to do? What did it do instead?’

What to look for

Display a sprite on the screen with a simple task (e.g., move 10 steps, say 'Hello'). Ask students to hold up fingers indicating which block category (motion, looks, events) they would use first to start the programming.

• Apply
• Analyze
• Evaluate
• Social Awareness
• Self-Awareness

Activity 03

• Think-Pair-Share
• 20 min · Whole Class

Think-Pair-Share: Resilience Strategies

After a challenging coding session, students share one thing that went wrong and how they felt. They then brainstorm a list of 'Keep Calm' strategies for when code doesn't work, which is displayed in the classroom.

Predict what a simple sequence of blocks will make a sprite do.

Facilitation Tip

During Resilience Strategies, give specific praise when students say things like, ‘I tried one block at a time and it worked.’

What to look for

Present a short program with a deliberate 'bug' (e.g., sprite moves left instead of right). Ask students: 'What is the sprite doing that we didn't expect? How could we fix this specific instruction?'

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

A few notes on teaching this unit

Start by normalizing mistakes: share your own ‘buggy’ code and solve it in front of them. Teach debugging as a structured process, not trial and error. Avoid rushing to fix errors for students; instead, guide them with questions like, ‘Which block seems to be causing the problem?’ Research shows that students who practice debugging regularly develop stronger computational thinking skills over time.

Successful learning looks like students testing code in small steps, explaining their fixes clearly, and persisting after setbacks. They should confidently use vocabulary like ‘detach,’ ‘isolate,’ and ‘test’ when discussing their programs.

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Watch Out for These Misconceptions

• During Bug Hunt, watch for students who erase the entire program when they encounter a bug.

  Prompt them to detach one block at a time and test, reminding them that professionals do this too.

• During The Debugging Doctor, watch for students who guess fixes without testing their ideas.

  Have them physically test each change and describe what happened before moving to the next.

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Methods used in this brief

• Simulation Game
• Role Play
• Think-Pair-Share