From cars to kettles and cranes to drills, machines do useful work in homes, factories, schools, and even on construction sites! But what powers machines? How do wheels work? And why exactly are screws so important? Questions like these and more can be found in this book, as readers learn about the numerous machines that make many important functions work--from toothbrushes to Ferris wheels--throughout the world. With interesting illustrations, fascinating facts, achievable text, and an eye-catching format, this book will be sure to entertain and intrigue readers from start to finish.