Here are questions to ask a student who is stuck, or who needs an idea to spark activity.
If one of the strips is fastened with two fasteners so it doesn’t move: how can I change this strip so it can move?
Show me how one piece (the input) makes another one (the lever) move.
Does the input move in the same direction as the end of the lever?
Can you change this so the input will make the lever go in the opposite direction?