Traffic lights, a cake recipe, a bus-stop announcement: each one follows a fixed order of steps. What happens if one step is missing or in the wrong place?

Today we write precise step-by-step instructions, break one on purpose, find the bug, and fix it. Then we try the same thinking on a robot route on the board.

Watch how I write steps for watering the classroom plant. Which details would you keep, and which would you leave out?

Look at the classroom task on the board. With your group, call out steps you would keep and steps you would leave out. Be ready to say why.

Quick class vote first: which change is most likely to make a job fail — a missing step, steps in the wrong order, or a wrong direction? (An extra step that does nothing is usually clutter, not a bug.)

Your group has one task card. Work through these jobs in order:

1. Write a clear algorithm on the step cards (5 to 8 steps).
2. Test: one person follows the steps exactly while the others watch.
3. Break exactly one step so the job fails.
4. Swap card packs with the group you are paired with.
5. Find and fix their bug.
6. Test again to check the fix works.

On your Investigation Journal page, record four short notes like the board example. Keep each note to one or two lines: your group's steps, the bug you found, the fix that worked, and one detail you left out on purpose.