Teach Your Elementary Class About Capacity with an Experiment

What is Capacity?

Capacity is the” fullness” of a container. In this activity, students will discover how much a container holds, what

51900 capacity lg

could change that answer, and how to measure capacity in standard units.

Let’s Begin With a Story

Gather your students together and share with them a book that demonstrates capacity.


Room for Ripley by Stuart Murphy. A boy named Carlos pours cups, pints and quarts of water into a fish bowl to get ready for his new guppy.

Mr. Archmedes' Bath by Pamela Allen. Mr. Archimedes is tired of cleaning up the mess from an overflowing bath. Who is overflowing the bath?

Who Sank the Boat by Pamela Allen. Five animals go for a boat ride. Who sank the boat?

How Much is Too Much?

After sharing the story, tell the children that they are going to work in groups to find out about capacity. Provide each group with a container e.g. a margarine tub or yogurt container. Put a mark on the container close to the rim. Fill the container with water to that mark .(Hint: have the students work over a bowl or large container to keep the water off the floor!) Invite the students to gently drop small objects (centicubes, plastic teddies, pebbles, shells) into the container. How many does it take to overflow the container? Change the order of objects. Is the result the same?

Continue With the Experiment

Next tell the students that they are going to find out which containers hold more. At the water table show the students a plastic water pitcher and a variety of different sized containers. Ask which containers will hold more water than the pitcher, and which containers will hold less water than the pitcher – this is a great activity to include in a lesson plan on greater than/ less than. As the students take turns to discover the answer, have them place a "holds more" or "holds less" sign beside each container.

Students should be allowed to freely experiment with pouring water from one container to another, and to discuss their findings with the teacher and with each other.

Introducing Standard Units of Measurement

Show your students a cup, a pint and a quart container. Explain to them that you need to have measures that are the same, so that everyone understands exactly how much liquid, flour etc you would need to follow a recipe, for example. If you did not have a "standard" set of measures you would have to say "Add two yogurt pots of milk and one margarine container of flour", and these might be all different sizes.

Fill the cup measure with water, (you could also try rice or sand). Then demonstrate how many cups it would take to fill the pint. Then how many pints to fill the quart. Make a chart to show the findings. Invite the students to go to the sand table or water table to try these measurements for themselves.


Observe the students while they are engaged in the interactive capacity activity. On a checklist record:

  • Does the student compare the capacity of two containers accurately?
  • Does the student understand the capacity of a cup, a pint, a quart?
  • Does the student understand which container holds more /less?
  • Does the student understand why it is important to use standard units of measure?


Read the book again, and discuss how capacity was an integral part of the story. Make a list of things where you need to use capacity measurement.


Picture credit: ETC Clipart, https://etc.usf.edu/clipart/51900/51900/51900_capacity.htm

Article written based on personal classroom experiences of the writer.