The scientific concepts of pushing and pulling are explained in this book which is one of a series intended to encourage children to explore the science of the world around them. The concepts are explained simply and are supported by activities on every page. Activities are suggested using a variety of simple devices to establish the force of an object such as: the difference in resistance between a heavy and a light book; rubber bands taped on to a saucer and a plate to see which band stretches the most; a gravity test; a test to see how some objects change shape when pulled or pushed; water in an inflated balloon gushes out when holes are made in the balloon; the effect of magnets on each other; the pushing movement of a root growing in water. These simple experiments help to understand what makes a hovercraft float, how a bow and arrow work, what happens when you squash air and what causes a tornado. There are also "test your knowledge" questions in "Did You Know" boxes.