1. Pie Charts

2. Why a Pie Chart? Very visual Easy to read
Slices show clearly how the data is distributed

3. Data for a Pie Chart Favourite Drink Frequency Milk 7 Orange 9 Cola 13
Water 6
Tea 2
Other 3
Usually given in a table format
This data was obtained from a class survey on “Favourite Drinks”
How many people said they preferred this drink
These are the answers given
Other allows for “unexpected” answers

4. 1 Work out the slices Favourite Drink Frequency Milk 7 Orange 9 Cola13
Water 6
Tea 2
Other 3
We need to calculate
the size of each slice in
the pie chart
40 people responded
to the survey
If very person had their
own slice, each would
get the same
X 360º
of the circle
= 9º
Total 40

5. If 1 person is 9º Favourite Drink Frequency Milk 7 Orange 9 Cola 13
Water 6
Tea 2
Other 3
Angle
7 x 9
= 63º
9 x 9
= 81º
13 x 9
= 117º
6 x 9
= 54º
2 x 9
= 18º
3 x 9
= 27º
Total 360º

6. 2 Draw the Pie Chart Use compassesx x
Use compasses
Draw a circle with centre on the mark
Mark a centre for the Pie Chart
Or draw around an Angle Measure

7. 2 Draw the Pie Chart Draw line vertically from centre to circumference
Draw LARGEST slice first
i.e. Cola = 117º
Cola x
Label the slice ‘Cola’
Do not enter the angle or the frequency!

8. 2 Draw the Pie Chart Draw NEXT LARGEST slice i.e. Orange = 81º
Turn Protractor so that
0º marker is at the end
of line just drawn
Cola
Orange

9. 2 Draw the Pie Chart
Then Milk = 63º
Cola
Milk
Orange

10. 2 Draw the Pie Chart
Then Water = 54º
Water
Cola
Milk
Orange

11. 2 Draw the Pie Chart
Then Other = 27º
Other
Water
Cola
Milk
Orange

12. 2 Draw the Pie Chart The LAST slice is already drawn – just check it
Tea = 18º
Tea
Other
Water
Give the Pie Chart
its Title
Cola
Milk
Orange
Class 7A’s Favourite Drink
Remove the small guide marks carefully