Our project involved flight. We began by trying to make a plastic straw fly through the air, with no success. We briefly talked about ways to make it work. Finally, we cut index cards into strips and make a large paper circle and another smaller one. We taped them to the ends of the straw and flew them again. What a difference it made! We decided it must have something to do with the air passing through the circles!
Here's a video to explain the science and so that you can see the creation in flight - or make one of your own!