## Lesson: Measuring and Comparing Weight and Capacity Developing the Concept

Children are becoming familiar with the units used to measure different things. In this lesson they will learn about measuring capacity in cups, pints, quarts, and liters.

Materials: 1-cup container, 1-pint container, 1-quart container, and 1-liter container; water colored with food coloring; one tall, thin container (like a bud vase) and one short, wide container with a greater capacity; other containers of various capacities

Preparation: none

Prerequisite Skills and Concepts:

• Say: Today we are going to learn to measure how much a container can hold. How much a container can hold is called its capacity. Let's compare how much water each of these containers can hold.
Hold up the tall, thin container and the short, wide container. Have the children predict which they think will hold more. Fill the taller container with water and then pour it into the short container.
• Say: The taller container holds less than the short container. That means the height alone of a container does not determine how much it can hold. Help children see that a short, wide container can have a greater capacity than a tall, thin container. Now let's compare the amount of water that each of these containers can hold.
Show children the 1-cup, 1-pint, 1-quart, and 1-liter measures. Name the measures as you hold them up for children to see. Remind children that cups, pints, and quarts are all part of the same measurement system as inches and pounds—the customary system. A liter is part of the same system of measurement as centimeters and kilograms—the metric system.
• Ask: Let's look at the cup, pint, and quart containers first. Which of these containers can hold the least?
Children may say that the 1-cup container can hold the least. If they don't say this, lead them to this conclusion.
• Ask: Which of these containers can hold the most?
Children may say that the quart container can hold the most.
• Ask: How many cups do you think it will take to fill the pint container?
Elicit the student's predictions and then show that 2 cups will fill the pint container.
• Ask: How many pints will it take to fill the quart container?
Elicit the student's predictions and then show that 2 pints will fill the quart container.
• Ask: If 2 cups fill the pint container, and 2 pints fill the quart container, how many cups do you think will fill the quart container?
Elicit the student's predictions and then show that 4 cups will fill the quart container.
• Say: So 2 cups = 1 pint, 2 pints = 1 quart, and 4 cups = 1 quart.
• Ask: Now, let's compare a quart and a liter. How can we find out which of these containers can hold the most?
Children may suggest that they can fill one of the containers and pour it into the other one to see which one can hold the most.
Fill the quart container and then pour the contents into the liter container.
• Ask: Is the liter container completely filled?
Children should notice that it is not quite full. If they don't see this, ask a volunteer to add more water to the liter container until it is full. Then pour the contents of the liter container into the quart container, without overflowing it. Children should see that there is a small amount left over in the liter container, indicating that the liter container holds slightly more than the quart container.
• Say: So, the liter container holds the most.

Wrap-Up and Assessment Hints
Children benefit from doing many hands-on activities with measurements. You may wish to have the class make batches of bread or cookies to have them work with cup, pint, and quart containers. These hands-on activities make it easier for children to remember equivalent measurements, and they also give you the opportunity to observe children's mastery of the concepts.