Aiming to help children understand everyday objects and events around them, this book on forces and machines is one of a series which introduces young readers to basic scientific concepts. The book contains activities so that the reader can test out the theories for themselves. An activity to test friction is illustrated using a rubber, a stone, a small piece of wood and an ice cube. These are placed in a line on a smooth wooden board which is elevated on one end to create a slope. The test is to discover which object moves the easiest on different surfaces. Using a lever to lift a book, an experiment is done to prove that the nearer the fulcrum is to the load, the easier it is to left the load. Two further scientific activities are explained to show how pulleys operate and how to make a lift using a knitting needle, a cotton reel, string, a plastic cup with sand and a box filled with modelling clay.