Master all kinds of measuring as you lift over 150 flaps in this informative book. There are speeds to calculate, thermometers to read, and lengths to measure with a handy pop-out ruler! All the major units and instruments used for measuring length, temperature, time, weight, and volume are covered. Hands-on interactive flaps show familiar real-world examples that make it easier for children to understand why and how we measure things. Also covers the differences in US customary and the metric system units of measurement.