When my daughter was in preschool, one of the moms (who happened to be a science ed specialist) did a project with the whole class. It was brilliant. She taught the kids how to work a catapult (made with a plastic spoon, I think) and, over two years later, my kid still talks about that day.
So, I was not too surprised when the girl said recently: "I want to make a catapult!" A quick Google search turned up instructions for one made out of craft sticks and tape. Now that is my kind of project. Historically I've not been too handy with 3-dimensional construction, but I'm up for anything that requires tape!
We started by making three congruent triangles and followed the directions through the next step. Suddenly, recognition!
"Hey look at what we've made!" I exclaimed. "It's a...?"
"Tetrahedron!" the kid laughed.
Not surprising -- triangles are the strongest shape, and it was fascinating to see how strong they really were, even given the modest construction materials.
We used a simple origami box we had lying around as the catapult cup, and wondered if a wider arm would fling objects further.
We love our new catapult and have had many hours of enjoyment flinging unifix cubes around the living room. Now that is math in action, lol!