## Measurement: Overview

Children are first introduced to measurement by using nonstandard units to measure length. You can use informal units of measure, such as linking blocks, paper clips, pencils, erasers, and crayons to help children understand the concept of measurement and to discover the usefulness of standard units of measure. When children use paper clips of different lengths to measure length, they can see that they will get different measurements for the same item. After children have worked with nonstandard units of measure, you can introduce an inch ruler as a tool for measuring standard units. Teach your children that when they measure with a ruler, they need to make sure that the left end of the ruler is aligned with the end of the item they are measuring.

The ruler is used to introduce children to measuring inches and feet. Similarly, a centimeter ruler and meterstick are used to introduce children to measuring in centimeters and meters. Begin by teaching the smallest unit first—the inch or the centimeter. You can use small items to familiarize your children with the sizes of these units. Once children have a solid grasp of the size of an inch or a centimeter, they will be able to estimate measurements using these units. When children have mastered inches and centimeters, they will learn to associate these units with the larger units of feet and meters. Providing measurement of classroom objects that are approximately one foot or one meter is a necessary step in helping children visualize the size of these units. Once they can measure length, you can introduce perimeter to children. Perimeter is the distance around a plane shape.

Measuring weight in pounds and mass in kilograms are concepts that are also introduced in this chapter. To understand the concept of one pound, children can compare items that weigh less than one pound to those that weigh more than one pound. Similarly, to understand the concept of one kilogram, they can compare items that are less than one kilogram to those that are more than one kilogram. At this point, children do not need to find exact measurements in pounds or kilograms. Having several items in your classroom that weigh either less than or more than a pound or are less than or more than a kilogram will help children become familiar with these units of measure.

Another aspect of measurement that is introduced in this chapter is capacity. Capacity is a measurement of how much an object can hold. At this level, children will need to learn how many cups are in a pint, how many pints are in a quart, how many cups in a quart, and how much a liter container holds. Having children measure the number of smaller units that fit into the larger units can help them understand capacity. Once they have found equivalent capacities through hands-on experiences, they will have an easier time solving math problems.

A thermometer is a measuring tool that most children are familiar with. They may have observed family members using thermometers or have learned to read a thermometer to find the outside temperature. Provide children with opportunities to read a Fahrenheit thermometer. Have a daily reading of the outdoor temperature and compare the temperature where you live with temperatures across the country. To reinforce the idea that temperature affects daily life discuss how the temperatures in different places affect the outdoor activities in which people take part.

As your children complete this chapter, they will have developed quite a repertoire of measurement skills. They will also have learned about the various tools used to find the different kinds of measurement. They should be able to select appropriate units to obtain a given measurement. Having children understand that they should use feet instead of inches to measure a room—or that they should use quarts instead of cups to fill a fish tank—is best developed through hands-on experience. For example, you can have one group of children use a smaller unit of measure and have another group use a larger unit so they can see which unit gets the job done faster. This skill is one that develops over time as children gain experience with measuring activities.