A pie chart is a circular graph that is divided into sectors or slices to illustrate numerical proportion. Each slice's central angle represents the quantity's percentage of the whole. To create a pie chart, you calculate the percentage of each category by dividing its value by the total value. You then multiply the decimal percentage by 360 degrees to determine each slice's central angle. A pie chart visually compares the proportional relationship of parts to a whole.

1. PIE CHART

2. WHAT IS A PIE CHART?
A pie chart is a type of graph in which a
circle is divided into sectors that each
represent a proportion of the whole
ORIGIN
1920s: because of the resemblance of the
graph to a pie divided into portions

3.  STEP 1:
Start by adding all of the data in order to get a
grand total.
 STEP 2:
Divide the value for each category by the final
total. This will result in the percentage of the
category in decimal form. Multiply the decimal
form by 100 to get the percentage form.
HOW TO WORK OUT
THE PERCENTAGE
FOR PIE CHART

4.  STEP 3:
Check to make sure the percentage total to
100%. If they don’t redo the calculations to
find the error.
 STEP 4:
Use the percentages to calculate the angles
necessary to draw a pie chart.

5. Category Amount Percentage of
sector
Raw food $28,000 ($28,000/$60,000)x100%
= 47%
Salary of workers $18,000 ($18,000/$60,000)x100%
= 30%
Preparation materials $6,000 ($6,000/$60,000)x100%
=10%
Rental and utilities $8,000 ($8,000/$60,000)x100%
=13%
Total Amount: $60,000 Total percentage: 100%
EXAMPLES OF HOW TO WORK OUT
PERCENTAGES IN PIE CHART

7. oTotal angles should add up to 360°
HOW TO CALCULATE
AN ANGLE OF PIE

8. Category Amount Angle of each
sector
Raw food $28,000 ($28,000/$60,000)x360°
=168°
Salary of workers $18,000 ($18,000/$60,000)x360°
=108°
Preparation materials $6,000 ($6,000/$60,000)x360°
=36°
Rental and utilities $8,000 ($8,000/$60,000)x360°
=48°
Total Amount: $60,000 Total Angle: 360°
EXAMPLES OF HOW TO CALCULATE AN
ANGLE OF A PIE CHART

10. WHAT IS A BAR CHART?
• A bar graph is a chart that uses either
horizontal or vertical bars to show
comparisons among categories.

11. shows the specific
categories being
compared
shows the specific
categories being
compared
represents a
discrete value.
represents a
discrete value.
AxisAxis
AxisAxis

13.  Single bar graphs are used to convey the
discrete value of the item for each
category shown on the opposing axis.

14.  It is also possible to draw bar charts so
that the bars are horizontal which means
that the longer the bar, the larger the
category.

15.  A grouped or clustered bar graph is used
to represent discrete values for more than
one item that share the same category.

16.  Some bar graphs have the bar divided into
subparts that represent the discrete value
for items that represent a portion of a
whole group.