While building a soapbox racing car, a pair of friends provide an easy-to-understand lesson in how simple machines are all around us, making our work more efficient. Michael and Luci show readers that a broom is a lever, nails are wedges, and a screwdriver is both a lever and a wheel and axle. The two also prove that curious children can be just like scientists, making observations and using how and what questions to explore physical science principles they encounter all the time. Michael's Racing Machine is part of the I Wonder Why book series, written to ignite the curiosity of children in grades K–3 while encouraging them to become avid readers. These books explore the marvels of light, color, machines, sound, and other phenomena related to physical science. Included in each volume is a Parent/Teacher Handbook with coordinating activities. The I Wonder Why series is written by an award-winning science educator and published by NSTA Kids, a division of NSTA Press.