Pumpkin π

A Multi-Grade Math Activity

Here is a hands-on activity that allows

students to explore a number of concepts, depending on the grade you teach: Ratios Circumference and diameter Scatterplots Linear Functions Slope

Overview

If your class is planning a trip to the pumpkin

patch, gather as many different size pumpkins.

Measuring tape Two-column chart for gathering data Larger poster for displaying data graph Optional: Graphing calculator or graphing

software

Materials

Procedure

Step 1Have students measure the diameter of the pumpkin. Have them find the widest length across the pumpkin.

Procedure

Step 2Have students measure the circumference of the pumpkin. Have them find the widest length around the pumpkin.

Procedure

Step 3Have students combine their measurements into one data table. Make sure they enter the correct data in the appropriate column. Make sure their measurements are in the same units.

Diameter (in.)

Circumference (in.)

Procedure

Step 4Graph the data as a scatterplot. If your class hasn’t covered this topic yet, simply graph the data for the students or use a graphing calculator or spreadsheet. Choose an appropriate scale.

Procedure

Step 5Try to find the line of best fit either visually or quantitatively. Ask students to interpret what the linear graph means.

Conclusion

The ratio of Circumference to Diameter is π, which also happens to be the slope of this line:

C = πdThe secret to the Pumpkin π is in the ratio.

Optional

Complete the activity with some real pumpkin pie for students to share!