Micro:bit Reaction Challenge

Overview

Students work in pairs to design, program and test a BBC micro:bit reaction-time game. They apply a design process by identifying a need, planning an algorithm, using inputs and outputs, testing a solution and suggesting an improvement.

Learning intentions

Students will:

• explain how a micro:bit uses inputs, processing and outputs.
• design an algorithm using events, conditions and variables.
• create and test a simple reaction-time game.
• work collaboratively to evaluate and improve a digital solution.

Success criteria

• I can describe what the micro:bit senses, processes and displays.
• I can create a clear sequence of instructions for my game.
• I can use an input and an output in my program.
• I can test fairly, identify a problem and suggest an improvement.

Curriculum links

• Digital Technologies — design and produce a digital solution for a defined purpose.
• Digital Technologies — represent algorithms using sequence, events and decisions.
• Digital Technologies — use digital systems safely and collaboratively.
• General capabilities — computational thinking, problem-solving, collaboration and critical thinking.

Lesson structure (51 minutes)

1. 0–5 min · Hook and challenge. Open with the reaction-game hook and challenge question and demonstrate a micro:bit showing a countdown before displaying a symbol. Students predict how the device could know when a player presses a button and discuss what would make the game fair.

2. 5–12 min · Teach the system. Use the input–process–output teaching slides to model the sequence: the micro:bit waits, detects an input, processes the event and displays an output. Introduce key terms—input, output, event, condition, variable, algorithm and test—and show a simple flowchart. Students identify the input, process and output in the demonstration.

3. 12–17 min · Plan in pairs. Distribute the micro:bit game design worksheet and revisit the planning instructions and success criteria. Each pair chooses roles such as programmer and tester, sketches a reaction game, writes the steps in order and predicts one possible problem. Students must include a start signal, a button input and a visible result.

4. 17–35 min · Build and test. Display the MakeCode build sequence while pairs use one BBC micro:bit and a suitable computer or tablet to create their game. Students build the simplest working version first, download or transfer it safely, test it several times and record observations on the worksheet. The teacher circulates, asking: “What is the event?”, “What happens if the button is pressed at the wrong time?” and “How will you know the program worked?”

5. 35–43 min · Improve through testing. Show the debugging prompts and fair-testing slide. Pairs swap devices or demonstrate to another pair, who follows the instructions and gives one strength and one suggestion. Students make one purposeful improvement, such as adding a countdown, changing the display, preventing an early press from counting or recording a score.

6. 43–48 min · Share and evaluate. Use the share-back prompts to invite three or four pairs to demonstrate. Students explain their algorithm, identify the input and output, and describe the change they made after testing. The class compares which design was easiest to understand and why.

7. 48–51 min · Exit assessment. Finish with the reflection prompts exit-ticket slips. Students respond to: “What input did your game use?”, “What output did it produce?” and “What would you improve next?” Collect the slips as they pack away devices safely.

Safety

• Handle micro:bit boards, batteries, crocodile clips, and computers carefully.
• Keep liquids and food away from all equipment.
• Check all connections before powering on devices.
• Do not put batteries or any components in your mouth.
• Report any damaged wires, hot batteries, or unusual smells immediately to the teacher.
• Unplug or switch off all equipment when finished.
• Follow teacher instructions when moving around or troubleshooting during the lesson.

Resources

• One BBC micro:bit per pair, with USB cable and battery pack if available
• Computers or tablets with the approved block-based micro:bit programming environment
• the complete micro:bit reaction-game slide deck
• the micro:bit game design worksheet
• the reflection prompts exit-ticket slips
• Projector or interactive display
• Headphones if the programming environment includes sound
• Device charging and storage area
• Pre-tested starter program or teacher demonstration micro:bit

Assessment

• During planning, check that each pair identifies a purpose, input, output and ordered algorithm on the worksheet.
• During building, observe whether students can explain their event and debug by changing one part of the program at a time.
• Use the exit slip to assess understanding of inputs and outputs, testing and improvement. Note students who need further support with sequencing or event-based programming.

Differentiation

• Support students with a partially completed starter program, a visual input–process–output model and a word bank. Provide a four-step planning frame: start, wait, detect, display.
• Pair students strategically and assign clear roles; allow students to rehearse the algorithm orally before coding. Provide teacher or peer support for connecting, transferring and safely handling devices.
• For students requiring additional accessibility support, use enlarged instructions, keyboard alternatives where available, reduced writing demands and verbal responses recorded by a partner.
• Extend confident students by adding a score variable, a random delay, an early-press message or two levels of difficulty. They should explain how their added feature changes the algorithm and affects fair testing.