Circle graphs are used to show how the whole of something can be divided into parts. They can also be described as pie charts and this may be one way to introduce circle graphs first because students can relate this to the real world when they envision a pizza pie as the whole and each piece as the parts. In class today we learned how to make circle graphs with
elementary students so that they can visualize and hopefully understand how
this type of graph works. The entire class was given a bag of M&M’s and
told to count how many of each color they had. We then combined all our data
together to find out what the total number of each color M&M’s our class
had. Before we began our circle graphs we first put our data into a bar graph
so that we could see the different classifications that we were working with,
for instance; there were green, brown, red, yellow, orange, and blue M&M’s
but, also to visualize the differences between the amounts. We colored our bars
the color of the M&M.
We then CUT OUT each bar graph and taped them together to make a circle. To do this correctly, you will need strips of paper that represent a base ten block so that you will have an accurate amount when you’re transferring your data to a circle graph. Remember, a circle graph is considered one whole and all the parts add up to that whole. That is why it is easier for young children to break the information into base ten blocks because each base ten block represents 10 of something or 10%. Using circle graphs in this way can be a great springboard for learning percentages.
Remember, a pie chart is not always the best choice for your data. Here's some simple questions to ask yourself when deciding whether a pie chart is the best choice: Do the parts make up a meaningful whole? Are the parts mutually exclusive? Do you want to compare the parts to the whole? Do you have 7 or fewer different parts? If you answered yes to all of these then a pie chart is for you!
Here's a great website to use with the students to make a circle graph once they have done this lesson.



