Pick a dry bean as your seed. Choose wind or water for your seed. Sketch a plan for your seed on paper. Add paper wings, tissue fluff or a foil boat. A grown-up helps with tape and scissors. Test it: drop it, or float it in a bowl. Change one thing and test again.
Safety first
A grown-up uses the scissors. The bean is for building, not eating. Wipe up any water spills. Wash your hands when you finish.
For a grown-up
Ask: what shape did you choose, and why? Ask: what changed when you tested again? Praise plans that change after a test.