Students will measure round objects to determine the circumference and diameter, and use the data to explore geometric concepts of the circle with statistics.

Before the Activity

See the attached PDF file for detailed instructions for this activity

Print pages 148 - 149 from the attached PDF file for your class

During the Activity

Distribute the pages to the class.

Follow the activity procedures:

Measure the diameter and circumference for each round item and record the values in a table

Explore the relationship between the circumference and diameter

Observe that the ratio of circumference to the diameter is the same for all round items

Plot the circumference versus diameter data

Draw a best-fit line and determine its slope

Measure the diameter of the cardboard paper towel tube

Use the graph to estimate the tube's circumference

Use the calculator to find an equation for the line

Use this equation to predict the circumference of the tube

Measure the circumference of the tube and compare it with the prediction and the estimate

Similarly, determine the measure of the diameter of the oatmeal box

After the Activity

Students complete the Student Activity pages.

Review student results

As a class, discuss questions that appeared to be more challenging