You would use circle graphs for the following reasons:

• They are easy to read because each piece of the pie represents a percentage of the whole.

• They use the concepts of calculating percents and measuring using degrees, both essential math skills.

• They show the whole as being 100 percent.

This is how to make a circle graph:

1. Change each of the data values into a decimal and a percent by dividing the part by the total.

2. Convert decimals to degrees by multiplying 360° by the decimal value.

3. Using the center of your circle, draw one radius.

4. Put the foot of your protractor on the radius with the center point of the circle touching the center foot of the protractor.

5. Measure the number of degrees for the first data point and draw a line.

6. Continue this process until all of the segments are drawn.

7. Label the segments or make a key for the graph.

Mr. Jordon surveyed his class about their favorite sport. Here are the results.