When you make a pie graph, you are really interested is visualizing what the percentage part each piece is of the whole. The visual imagery of a pie being divided into servings is very intuitive. It makes it easier to understand your data via of a picture of pieces being taken out of a whole pie. Remember that the whole pie represents 100% or everything that is possible.
First study the example provided. It is supported by the data and labels on the left. If you supply your own data, you can create and print a chart that is customized for your own purpose. Everything that is in gray can be changed, including the title. If you have fewer than 10 data points, then just delete the data points at the bottom and work up. A print button is provided for printing your completed graph.
When you make a pie graph from your data, you will have a much better idea of how much of each component is required to make the whole.