Students revisit the sled that won’t go down the ramp, and invent a new way to “help” it move by putting rollers under it.
Review of the sled problem:
Set up a ramp per pair of students; make sure the sled cannot initially slide down, due to the combination of surface and slope. Students may use plain cardboard sleds or the sleds they redesigned in Lesson 5. Review what happened when the surface was too rough and/or the slop wasn’t steep enough to make the sled move on its own:
A new way to get it to move.
Provide skewers, straws, stirrers, pencils, crayons, paper clips, paper fasteners, masking tape. Ask:
Lead a discussion of the methods students used, and which ones worked. Introduce the words roll and roller.
Further experimenting and recording results:
If students haven’t all tried rollers, provide time for them to test this idea, as well as others that students have come up with. Then ask students to record their findings on the worksheet
Make a class chart to describe what happened as a group.
Students should keep their materials in the storage bags for use in the next lesson.