My students had so much fun working on the last STEM challenge of the year....catapults! They did some research on catapults, and then I gave them a toilet paper tube, paint stirrer, rubber-band, and a marshmallow. I told them that their challenge was to see who could launch a marshmallow the farthest using the given items.
This was a super easy project to put together, and the groups did a great job trying different options to create the catapult!