The book shows how kids learn about engineering science, and how their play and solutions equip them to understand grown-ups' actions later. Kids on teeter-totters learn about high-rise counter-balanced construction cranes; kids pushing other kids on wagons understand discussions of rockets launching heavy payloads into space; kids making snow-balls or making mud-clods (wet or dry, to throw at their buddies) learn about cohesion, plus about ballistics;...