Pinwheel spinner
Explorers (Foundation), mission E6 Wind & Spin, lesson 1 of 6.
Hook
You can’t see the wind, but you can see what it does! Blow and watch.
Fair test
Blow gently, then hard. Count spins in 5 seconds each time.
Bonus challenge
Make it spin the other way. What did you have to change?
The build
Pinwheel Spinner: Four angled paddles on an axle on a stand. Blow on it, or use a fan, and watch which way it spins.