An introductory video introducing the U.S. customary and metric units and which units measure length, mass, and volume. This video also appears in the strand Arithmetic and Pre-Algebra: Ratios and Proportions. [5:10]

In this lesson, students are introduced to the English system of measurement. It is 6 of 6 in the series titled "English System of Measurement."

In this lesson, you will learn to determine whether to find area, surface area, or volume in a given situation by thinking about what units are needed. [3:38]

In this lesson, you will learn to recognize common units of measurement by comparing them to everyday objects and events. [5:59]

In this video lesson, Sal uses different units to measure the same object, centimeters and rectangles.

This video will help children with measuring liquids in quarts and gallons. When both pairs of agents--Olive and Otto versus Oren and Olaf--capture pieces of the Blob, they visit the Mathroom to see who has more.

In this lesson, students see how to convert between square miles and square kilometers. It is 9 of 9 in the series titled "Converting Between Square Miles and Square Kilometers." [2:26]