Pie graphs Learning intention: Students will learn how to interpret pie graphs

Pie graph Circle graph Sector graph Use sectors of a circle to show sizes of parts The whole pie represents 100%

100 %

50%

25%

Pie graphs A pie graph is best used for showing percentages. It shows parts of a whole. In a pie graph each quantity is graphed as a sector of the circle. When a sector graph is created, each sector is constructed as a fraction of the whole.

Why pie graphs? The circle provides a visual concept of the whole (100%). Pie graphs are simple to use. Pie graphs convey a clear message to the user.

Pie graphs are used when there are no more than six components only—otherwise, the resulting picture will be too complex to understand.

Title Sectors Six types of sports are shown on the sector graph Key Graph Title – the title tells what the graph is representing. Sectors – Each sector is one part of the whole circle. It represents a particular category. Sector Labels – Each label tells what the sector represents. Labels 20% Percentage Sector graph or pie graph Sector graphs are used when there are no more than six components.

Some examples where a pie graph can be used Air composition Sports played by students  Favourite channel  Favourite TV show  Favourite pet  The percentage of different animals  Preferred juice

If there were 200 animals in the nature reserve how many were birds? This pie graph shows the proportion of each animal in a nature reserve and not their real numbers.

Calculate the number Percentage of lizards Total number of animals Question: If there were 200 animals in the nature reserve how many were lizards? Question: If there were 200 animals in the nature reserve how many were lizards? 1.

Calculate the number Number of wallabies Total number of animals Question: If there were 200 animals in the nature reserve how many were wallabies? Question: If there were 200 animals in the nature reserve how many were wallabies?

Calculate the number 58 insects 58 lizards 34 wallabies 18 possums 20 birds 12 spiders Answers

Calculate the percentage If there were 200 animals in the nature reserve what is the percentage of the birds? 1- Write the amount over the total as a fraction 2- Multiply by 100 Amount of birds Total 2.

Calculate the percentage If there were 200 animals in the nature reserve what is the percentage of the possums? 1- Write the amount over the total as a fraction 2- Multiply by 100 Amount of possums Total

Calculate the percentage If there were 200 animals in the nature reserve what is the percentage of the lizards? 1- Write the amount over the total as a fraction 2- Multiply by 100 Amount of lizards Total

The composition of the air Oxygen What is the percentage of oxygen? Question

The composition of the air Answer

A table is a grid of rows and columns into which data is placed. Row Column What is a table?

A table should have:  a clear and simple title  a set of rows and columns  headings for the columns. GasesPercentages The composition of air

Using a ruler, draw a grid leaving enough spaces for the data. At the top of the data table, write your title Label the columns and the rows The composition of the air Decide on the number of columns and rows Use the data in the graph to draw a table GasesPercentages Nitrogen78% Oxygen21% Other gases1% Write your data

Station 2 Station 3 Station 4 Station 1

Numeracy Across the Curriculum Interpreting pie graphs Designed for the Science faculty By Zani Alam