Standard Units of Measurement Background Information for Teachers and Parents

Grade Levels: K-3

Measurement is an important part of every elementary curriculum. Your children should become familiar with working with nonstandard and English/U.S. customary units and using different measurement tools such as rulers, tape measures, and yardsticks. The metric system is also an important part of elementary education and will be covered in a separate topic. Review with your children that length is how long an object is and the width is how wide an object is. The height is the measurement of how tall or high the object is.

Most students use nonstandard units when they first learn how to measure. Encourage them to use different objects to measure lengths. Explain that objects that are flat and straight work best when measuring length. The objects should be lined up, end to end with no gaps, next to the object they are measuring. Students should start measuring from the end of the object to get an accurate measurement.

Standard units of measurement are important because they provide reference points that everyone can use. Historically, an inch was equivalent to the width of a thumb and in many languages the word for inch is the same as the word for thumb. Similarly, the length of a person’s foot represented a foot. Since hands and feet differed in size, a more accurate system of measurement was necessary.

The customary units used in the U.S. include inches, feet, yards, and miles. Your children should know that 1 foot is equal to 12 inches. Your children should also know the abbreviations for customary units: inch (in.) and foot (ft). When young children use a ruler to measure, it should be stressed to line up the end of the object with the 0 on the tool. When they identify the number and mark on the ruler that lines up with the end of the object, they should record their results with both the number and the unit of measurement.

Your children should become familiar with the language and vocabulary associated with measurement. For example, about, close to, between, just under, less than, and greater than are all words used to help describe measurements. We recommend watching the Place Value movie together as a review for comparing large numbers. Encourage them to notice that many things do not measure to an exact inch or foot. Prompt them to use describing words to help explain how close the object is to the nearest inch or foot.

Encourage your children to explore the world around them and measure objects using nonstandard and standard units of measurement. They will begin to notice particular units and tools work better for different tasks.