Readers learn what the clock measures and why knowing how to tell time--in seconds, minutes, and hours--is important. They learn the history of the clocks, including sundials and hourglasses. They also learn how to read analog and digital clocks to tell time. Sidebars instruct math by showing readers how to add and subtract hours.

Readers learn what temperature is and why and how it is measured. They learn about the Celsius and Fahrenheit scales and where each is used. Readers learn about thermometers and how they help us in everyday life--from taking body temperatures to regulating how cool or warm our homes are.

Readers learn what gravity is and how it impacts weight. They learn about the US customary system and the metric system, where each is used, and the units of measurement in each system. Readers also learn about balances, scales, and estimating weights.