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Creating pie graphs

It is important that students understand the part-whole relationship that exists when creating a pie chart.

A circle, or pie, represents the whole of the data set (population or sample) that is the focus of discussion.

Usually the segments of a pie graph are labelled in percentages adding to 100% but fractions can be used.


The segments of a pie graph can be marked using a protractor and the percentage of 360 degrees that makes up the segment. However, it is also possible to create a pie graph with concrete materials. With small data sets and frequency data for each category, each value in the same category can be placed along a strip of paper in equal intervals.


Strip divided into 20 equally sized parts then shaded into one section of 5, the next of 10 and the last of 5.

Frequencies for categories.
Source: © Jane Watson.


The strip of paper is then rolled into a circle. Draw lines to connect the middle of the circle with the boundaries of the categories to create the pie graph.


Pie graph displaying proportions of one-quarter, one-half and one-quarter.

Pie graph created from the frequencies.
Source: © Jane Watson.

Sleuthing pie graphs

After reviewing the properties of a pie graph, students investigate another pie graph.

Curriculum links

Year 4: Construct suitable data displays, with and without the use of digital technologies, from given or collected data. Include tables, column graphs and picture graphs where one picture can represent many data values

Year 4: Evaluate the effectiveness of different displays in illustrating data features including variability