Use different-sized cups to demonstrate volume for the children. Line up cups of varying size. Be sure to include wide, narrow, tall and short cups. Fill two cups at a time with different amounts of water. Have the children guess which cups have the most water. Then further emphasize this demonstration by showing the class what happens when you pour water from one sized glass into another. Let the children try this on their own so they can understand how volume works in ways they might not expect. Use other containers, like bowls and pots, to help them understand the volumes of different shapes. If water is too messy for your preschoolers, use dry rice.
Use music to help your preschoolers remember the rules for volume. There are many songs available that teach educational concepts like math and science. Look for the appropriate song for your lesson plan on volume. One example of this is called "The Volume Song," found on the "Have Fun Teaching" website. This song teaches the equation for volume in a fun and easy-to-remember way. Many preschool lesson plans already include music, so the children should be used to the format. Teach the children the song or songs and have them take turns reciting them.
Find an educational computer game about volume. A common one requires the child to use the mouse to fill two different containers with water. One container can hold a large amount of water, about 5 to 8 quarts. The other container holds a small amount of water, usually 3 quarts. You have an unlimited supply of water. The goal of the game is to move the water from one container to the other in the attempt to get the required amount of water. This requirement may change based on the level the game is set to. This teaches preschoolers what happens when you empty one container of water into another. It also begins the preschoolers' understanding of measurement. Two examples of this online game can be found at Johnnie's Math Page and Kid's Math Games at the Netrover website.
Use art projects to teach volume. Draw and have your students draw a full-figured person. Then write the different quantities of volume on the appropriate proportions of the body. For example, the body would represent a gallon, the eyes a teaspoon, the mouth a tablespoon, the arms and legs a quart, the hands and feet a pint and the fingers and toes a cup. This type of visualization makes concepts easier for children to remember. Experiment with different art projects that work best for your classroom.
Make up a story expressing the different volume measurements. One example of this method is referring to a gallon as a special kingdom, with two queens to represent two quarts in a gallon. The queens each have a prince and princess; they each represent a pint. The princess's and prince's both have two children, who represent a cup. This story works by comparing the letters of two different words to make a memorable story.