It's about hands-on experience (Score 1)

The most important part is for the kids to get physically involved, no matter what you do. Start with folding paper airplanes -- show + have the kids do it themselves. Then take a piece of thin balsa wood 4" x 8" and cut a square out of one end. Trim the cut-out piece a bit, shape the other end into a point, put a rubber band across and wind the loose piece up in it to make a paddle-wheel boat for the sink or bathtub. Then let the kids make a flag or sail out of a toothpick and some paper. Then work up to the kits from Edmund's.