Provide preschoolers with yarn and invite them to cut off a length of yarn they think will wrap perfectly around the middle of a pumpkin. Have preschoolers test to see if their guesses were too short, too long or just right. Use a yardstick to measure the length of yarn that came closest to the pumpkin's circumference. Invite preschoolers to guess the height or weight of pumpkins. Use stacking inch cubes and bathroom scales to compare estimates to actual measurements. Encourage preschoolers to measure other pumpkins in the classroom the same way.
Cut open a large pumpkin. Invite preschoolers to get their hands messy and help you remove all the seeds and stringy pulp. Count how many seeds were inside the pumpkin. Wash the seeds and soak them overnight. Split open seeds the next day and let preschoolers use a magnifying glass to get a close-up look at the tiny plant growing inside the seeds. Take a few seeds and plant in a pot of soil. Let seeds grow during the school year and observe how new leaves form and how tall the plants get.
Remove seeds from one or two pumpkins. Invite preschoolers to help you wash the seeds. Mix 1 1/2 cup seeds with two tablespoons melted butter and 1/8 teaspoon of salt. Spread seeds out on a cookie sheet and bake at 300 degrees F until golden brown--about 45 minutes. Cool and enjoy at snack time.
Provide paint, yarn, felt, buttons, glue, glitter and other craft materials on an art table. Invite preschoolers to paint fun faces on their pumpkins. They can turn their pumpkins into scarecrows, dogs, cats, tigers, bears or typical jack-o-lantern faces. Preschoolers might decorate pumpkins by gluing on button eyes, felt noses and yarn hair. Allow students to think outside the box and paint pictures such as a cat sitting on a fence under a full moon or a haunted house on their pumpkins.