Page 493 - Canadian BC Science 9

Example
To learn how to make a circle graph from the data in Table 5, study the corresponding circle graph on the right as you read the following steps.
4. Draw a straight line from the centre to the edge of the circle. Use your protractor to measure 32° from this line. Make a mark, then use your mark to draw a second line 32° from the first line.
5. Repeat steps 2 to 4 for the remaining types of birds.
Table 5
Birds Breeding in Canada
Type of Bird
Number of Species
Percent of Total
Degrees in Section
Ducks
36
9.0
32
Birds of prey
19
4.8
17
Shorebirds
71
17.7
64
Owls
14
3.5
13
Perching birds
180
45.0
162
Other
80
20.0
72
Procedure
1. Use a mathematical compass to make a large circle on a piece of paper. Make a dot in the centre of the circle.
2. Determine the percent of the total number of species that each type of bird represents by using the following formula.
Percent of total 􏰀 Number of species within the type 􏰁 100% Total number of species
For example, the percent of all species of birds that are ducks is:
Percent that 􏰀 36 species of ducks 􏰁 100% 􏰀 9.0% are ducks 400 species
3. To determine the degrees in the section that represents each type of bird, use the following formula.
Degrees in 􏰀 Percent for a type of bird 􏰁 360° “piece of pie” 100%
Round your answer to the nearest whole number. For example, the section for ducks is:
Degrees for ducks 􏰀 9.0% 􏰁 360° 􏰀 32.4° or 32° 100%
perching birds
birds of prey
ducks
other
Species of Birds Breeding in Canada
owls
shorebirds
Instant Practice—Circle Graph
Use the following data on total energy (oil, gas, electricity, etc.) consumption for 2004 to develop a circle graph to visualize energy consumption in the world.
Table 6 World Energy Consumption in 2004
Area in the World
Consumption (quadrillion btu)
North America
120.62
Central and South America
22.54
Europe
85.65
Eurasia
45.18
Middle East
21.14
Africa
13.71
Eastern Asia and Oceania
137.61
Science Skill 5 • MHR 475