Rulers seem like such simple tools, but their importance can't be overstated. Without rulers, and the knowledge of how to use them, so many inventions, buildings, and other man-made achievements would just fall apart. In this volume, readers will review the basics of rulers and observe them being used by young student-scientists as well as by professionals in the working world. They'll even test out their own ruler skills as they find out that rulers rule the world of science!