World of Machines: An Introduction to Simple Machines for Young Scientists is an exploration of basic laws of physics, and the functions and uses of six simple machines. Students are introduced to simple fundamentals of matter, mass, density, inertia, force, the laws of motion, gravity, friction and work. They learn how machines reduce effort, then focus in on six simple machines: the lever, wheel and axle, pulley, inclined plane, wedge and screw. Let's Do This! activities give students opportunities to test out basic physics concepts in the real world and to experiment with each simple machine. The result is a grounding in the uses of simple machines to reduce effort and make it possible to carry out tasks that would not be possible without them. This can be an empowering experience! What is a machine exactly? Did you know that a scientist would call a wheelbarrow a machine? How about a nail, a doorknob, a shovel or a bicycle? Are these machines? If you said, "yes," you're on your way because . . . machines are things that help make work easier! Want to know more about machines and how they work? Then you're ready to explore the World of Machines.