Watch this. One small push at the side makes something else move. How can a push in one place make a different movement somewhere else?

Hands up: what everyday things turn one movement into another?

Watch the bird again. Where does the movement start, and where does it end?

Watch carefully while a simple moving picture is joined together. When the strip is pushed, which part of the bird will move?

In your group, build a lever-and-linkage moving picture so one input movement makes a clear output movement. Use at least one pivot. It is fine if the first pin position is awkward — adjusting is part of the engineering. Work in this order:

1. Agree what your scene is and what should move (for example a bird wing or a waving arm).
2. Use the pre-cut base and strip if you have them, or sketch lightly on card and cut the parts.
3. Join the moving part to the base with a split pin so it can swing.
4. Pin on the input strip the user will push or pull.
5. Test gently and adjust until the output is clear. Stop when you can name the input and the output.

Now investigate your own mechanism. You are the tester: change one thing and see what the mechanism tells you. Choose one thing about the input to change: how far you push, how fast you move, or which direction you go. Predict what the output will do, then try it. Try a second change after the first. On your Investigation Journal page, jot a quick prediction and what you noticed; you will draw the mechanism later.