Think like an algorithm

Suggested age: 8-12Length: 10 minutes

Put the steps in order so a machine can cross the street without being hit. One step out of place and it crosses on a red light.

Put the steps in order using the up and down buttons.

Teacher sheet

Goal. Understand that an algorithm is a list of steps in an order that matters, and that the machine does not fill in what is missing.

Questions to open the discussion

What happens if we remove the step about looking both ways?
The light is green but an ambulance is coming. Does the algorithm cover that?
What other step would you add?

The idea that should stick. The machine does exactly what the list says, no more and no less. What nobody wrote does not happen: the ambulance was not in the steps.

Chris Meniw Foundation Inc. · Free to use in classrooms. No permission or attribution needed.