When a child understands the parts-whole relationship, she acquires a foundation for mathematics, language and scientific discovery. Beyond addition, subtraction, fractions and time, this essential early concept opens the door for piecing words together to form sentences. Its applications in science include the biological understanding of body parts and chemical mastery of elements and compounds. Interactive lessons are an engaging way to teach the parts-whole relationship to preschoolers.

## Body

Adult humans have 206 bones, 32 teeth, two arms, two legs -- well, lots of parts that make up the whole body. Using the body to teach the parts-whole relationship is not only easy, but also free in most cases. Hold up a hand and point out the fingers, palm and knuckles. You might even talk about how these parts work together to make the whole hand grab, clap and do other actions. Introduce an art lesson where students draw the parts of their face or their favorite body part. Sing and dance to “Dem Bones” to demonstrate how various bones connect to form the human skeleton.

## Self

Each student is a social part of different whole groups: family, the preschool class and, perhaps, a play or church group. “The Family Book” by Todd Parr introduces young children to various families. Students will enjoy acting out animals they might see in groups at the zoo, such as schools of fish, a pack of wolves or a herd of elephants. To demonstrate parts-whole group relationships in the classroom, point out that everyone together makes up the preschool class and that each student is a part of the whole class. Then, divide students by gender or shirt color, explaining that each of these smaller groups is part of the whole class.

## Toys

Ask each student to pick out her favorite toy in the classroom. One by one, allow the students to name parts of the toy. For example, a car has wheels, doors and bumpers, while a block has sides and painted letters. Speaking of blocks, they can be used to build any creation students can dream up, so let students stack them as an additional parts-whole lesson. Puzzles are another effective example of how parts join to create a whole object. You can also talk about books. Present the parts-whole relationship by drilling down from the whole book to pages in the book, words on a page and letters in a word.

## Food

Cakes, fruits and pizzas are foods that students have likely seen cut and shared among family and friends. That makes them prime tools for teaching the parts-whole relationship. Cut large circles of paper into slices of pizza for each group of six to eight students. Set the whole pizza in the middle of each group and then instruct each student to take a part (a slice) to decorate with his favorite toppings. If school rules allow it, do the activity with real food.