Walnut shell or acorn top, toothpick, paper, clay
Using acorn tops or walnut shells, children can create boats that actually float! Take the clean, halved shell and place a small amount of clay in the bottom. Stick a toothpick in the clay. Cut a small square-shaped sail out of paper, put this sail on the toothpick by poking it through the toothpick. Put it in the water and watch it float.