Unique DIY String Light Poles with Concrete Base. These DIY string light poles are extra sturdy and they look unlike any string light poles we’ve seen, with tree trunks taking the place of wooden or metal poles in the concrete bases.
Balloon Rockets - I've done this in several science camps I've conducted. Kids have fun with it. But, when the balloon deflates it may fall off the straw because it's surface area changes - another good thing to show and explain to kids.