"Presents information on simple machines with a focus on wheels and axles. Explains what wheels and axles are, how wheels and axles work, and includes examples of past and present uses. Intended for third to fifth grade students"--Provided by publisher.
Note
Includes index.
Contents
What is a wheel? -- Wheels in time -- What is an axle? -- Rolling forward -- Modern wheels -- A wheel with teeth -- The future of wheels -- Gaining an advantage -- Surfing simple machines -- Science in action -- What have you learned?.