Unplugged Computational Thinking Seminar · Lesson 3: Sequences and Events
Turn the models from Lesson 2 into a sequence that starts reliably and responds to a user — traced on paper, or built in Scratch if devices are available.
Pairs predict a short instruction sequence, lay it out in order, then add a keyboard event — with command cards, or in Scratch if devices are available. Driver and navigator roles rotate after every successful test.
Ngā Whāinga Ako | Learning Intentions
Connect an event to an ordered sequence.
Predict and test what a short script will do.
Use pair-programming talk to explain code.
Do Now: What happens first?
7 min
when green flag clickedgo to x: -160 y: 0say “Kia ora!” for 2 secondsglide 2 seconds to x: 160 y: 0
Sketch the sprite’s start and finish positions.
Number the visible changes in order.
Predict what changes if the go to block moves to the bottom.
Activity 1: Five-minute interface tour
8 min
Look at the printed four-part diagram: stage (where the action happens), sprite list (who is acting), blocks palette (the instructions available) and scripts area (the instructions in order).
Navigator reads the four-block target above; driver points to where each block would sit in the scripts area.
Swap roles.
If your class has devices, open the Scratch editor (no login needed) to see the same four parts on screen — optional, not required for this route.
Activity 2: Build, run, explain
22 min
Assemble the four-block sequence exactly, using four instruction cards or a written list.
Act it out three times: one ākonga plays the sprite, resetting to the same starting position before each run, while a partner reads the instructions aloud in order.
Change the words and destination so the sequence communicates an original welcome or class message.
Partner trace: point to each instruction card while saying what state changes.
Copy your final instruction list into your workbook. If your class has devices, you can also build and run the same sequence in Scratch to compare — optional, not required.
Checkpoint: The sequence must reset before it moves. If it starts from wherever it stopped, the algorithm is not yet reliable.
Activity 3: Add a user event
16 min
when right arrow key pressedchange x by 10
Add the two-block script to the same sprite — or, on paper, lay the two command cards beside your sequence and have a partner call out the key press.
Test one press, then five quick presses. On paper, move a counter one step per call and mark each position. Record the expected and actual position change.
Change the key or movement amount, but only one variable at a time.
Ask a new user to start and control the project without coaching. Improve one unclear instruction.
Manaakitanga: A clear instruction respects the user’s time and confidence.
Exit: Trace the event
7 min
Complete: “When ___ happens, the program runs ___, then ___.” Name one block that makes the project repeatable and one test that proved it.
🎯 Curriculum Alignment
Designing and developing an outcome through spatial and product design, materials, foods, biotechnology, systems, or digital tools
Ākonga create and test their first digital outcome. See the unit map.
📦 Materials & Resources
Resources already provided: exact target blocks above (as instruction cards or a written list), paper for prediction and tracing. Devices and the Scratch editor are optional, for classes that want to compare the paper sequence to a screen version.
📊 Assessment and Success Criteria
Paearu Angitu | Success Criteria: I can start a script with an event, put blocks in a purposeful order, predict the result, and explain the sequence to a partner.
♿ Inclusion, entry and extension
Entry: Use a printed block order and let the learner direct a partner. On-level: Require a reliable reset and keyboard event. Extension: Add a second sprite that responds to a broadcast. Use stable driver/navigator roles, large cursor settings, keyboard access and a paper alternative for sensory or device barriers.
📋 Teacher Planning Snapshot
This route runs entirely on paper and instruction cards; Scratch access is optional, not required. Model only the first four blocks, then let pairs change purpose and wording. Check consent before any learner records a voice or uses another person’s image or reo. Lesson 4 makes repeated sequences more efficient with loops.
📚 Sources and teaching basis
Scratch for Educators. Ako is enacted by rotating the knowledgeable role; mātauranga Māori content is not required as decoration, and any local narrative or reo asset remains subject to local authority.