Paper-Cup Rocket

Japanese name: 紙コップロケット

Suggested ages: Older preschool and primary school children
Group size: 1–6 participants
Suggested time: 15-25 minutes
Location: A tabletop for making the rocket; a clear floor area for launching

Materials

An adult makes four short slits at equal intervals around the rim of one paper cup. Link the two rubber bands through one another.
Hook the linked bands into the slits so that they stretch in a cross across the cup's opening. Check that they are secure and decorate the cup with light paper.
Stand the other cup upside down on the floor as the launch base. Turn the banded cup upside down too and fit it over the base cup.
Once everyone nearby has moved back, press the upper cup downward and release both hands together. Keep faces away from above it and watch it jump straight up.
Give each person three launches before handing the space to the next person. If it does not jump, check the band arrangement. Collect all bands and paper at the end.

Preschool children: press an assembled rocket. Younger primary school children: decorate. Older primary school children: assemble and compare.