Ask, “What kinds of problems do we run into in the classroom?”
Select student volunteers to call out a few example problems (e.g., trash on the floor, the classroom getting too noisy, papers being left out, the lights being left on).
Work with the class to brainstorm the problems that bothers them in the classroom. List the problems on the whiteboard or poster paper.
Do not judge ideas as good or bad at this time.
Once you've gotten all ideas written down, read them aloud.
Discuss what accessories students could design for Dash that could help solve some of the identified problems.
Could Dash have a bulldozer to sweep the floor?
Could Dash have a hand to help turn off the lights?
Discuss how students could program Dash and Dot to demonstrate the accessory.
Could you use a nested loop to have Dash move back and forth while sweeping the floor?
Could you use an event handler to have Dot ask Dash to deliver something?
Could you use a conditional to have Dash react to obstacles while delivering things to someone?