Using Pumpkins of Varied Sizes, Students Estimate Weight and Number of Seeds, Then Test Their Hypotheses

from Education World ®

Grade Levels: K-2, 3-5, 6-8, 9-12

Objectives
Students will:

• make a prediction and test it,
• build place-value understanding as they count pumpkin seeds, and
• write a concluding statement that describes what they learned.

Keywords
pumpkin, hands-on, predict, prediction, hypothesis, seeds, measurement, weight, height, width, count, counting, place value, Halloween, fall, autumn, September, October, harvest

Materials Needed

• pumpkins of various sizes (Suggestion: one pumpkin for every two students.)
• Predicting Pumpkins work sheet ( PDF, 97K), one per student
• old newspapers (to cover the working surface and make activity cleanup easy)

Procedure

Gather pumpkins of various sizes. (Suggestion: one pumpkin for every two students.) Spread craft paper or old newspaper over surfaces where students will be working.
 

1. Display for students the variety of pumpkins you have collected. Ask students to describe differences among the pumpkins. Ask students to predict which pumpkin weighs the most.
   
   For upper elementary and above students, you might number each pumpkin and ask students to record an estimate of each pumpkin's weight. Choose one pumpkin to weigh in advance, so students have a point of comparison for their estimations.
    
2. Number the pumpkins you have gathered. (The numbers will be important as students fill out the activity work sheet.) Then provide each student or pair of students with a pumpkin. Have each student or pair/team record on the Predicting Pumpkins work sheet ( PDF, 97K) their pumpkin's measurements by:
   • weighing it,
   • measuring its height at its highest point, and
   • measuring its width at its widest point.
   
    
3. Ask students/teams to:
   • share their data,
   • predict how many seeds they will find inside their pumpkins, and
   • predict whether their pumpkins will have more or fewer seeds than other pumpkins.

   Have students record their predictions on the Make a Prediction section of the Predicting Pumpkins work sheet ( PDF, 97K).
    

4. Next, cut off a section from the top of each pumpkin. Have students use their hands to dig out the contents of their pumpkins. Then have them count the number of seeds in their pumpkins.
   
   Turn this activity into a lesson in place value. Have students arrange seeds in groups of ten on a small piece (half of an 8-1/2- x 11-inch sheet) of math paper, and circle each group of ten seeds. When they have ten groups of ten seeds on a sheet of paper, students start counting seeds on a new piece of paper, so each piece of paper contains 100 seeds (hundreds place value); each additional group of seeds that is circled on the final piece of paper will represent 10 more (tens place value); and each seed that's left over after all groups of ten seeds are collected will represent one (units place value).
    
5. When students are finished counting, have them record the number of seeds in their pumpkins on the correct line (the line that matches the number assigned to their pumpkin) of the Predicting Pumpkins work sheet ( PDF, 97K).
    
6. When all students/teams are finished measuring and counting, give each group an opportunity to share the data they collected. Students should record the data for each team's pumpkin on the correct line on the work sheet. When completed, the chart will reflect the following information about each pumpkin:
   • its weight
   • its height
   • its width
   • the number of seeds in it
   
    
7. When all data is collected and recorded, challenge students to analyze it. Does there seem to be a relationship between the height, width, or weight of a pumpkin and the number of seeds in it? Have students record their observations. Were their predictions correct?
   
   You might turn this into a think-pair-share activity: Have students work on their own to record their observations. Then have each student pair up with his or her partner from the counting activity and share their thoughts/observations. Then have each pair of students join another pair and discuss their observations. Then have each foursome join another foursome. Finally, discuss the results of the experiment as a class.

Extension Activities

Have students create graphs to show the data they collected. They might use the free and easy-to-use Create a Graph tool to make their graphs.

Bake the pumpkin seeds for a tasty snack. Click here for a recipe.

Assessment

Have each student construct a statement summing up his or her observations in response to the question Is there a relationship between the size of a pumpkin and the number of seeds it contains? Upper elementary students might write a more detailed summary to include what they predicted, did, and observed.