Reading and Interpreting Circle Graphs

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Reading and Interpreting Circle Graphs
7-4
Warm Up
Problem of the Day
Lesson Presentation
Course 2
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Warm Up Write each fraction as a percent.
1. 2. 3. Write each percent as a
fraction. 4. 20 5. 25 6. 60
75
10
40
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Problem of the Day Riddle When does 1 1 1
1?
1 ft 1 ft 1 ft 1 yd
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Learn to read and interpret data presented in
circle graphs.
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Vocabulary
circle graph sector
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A circle graph, also called a pie chart, shows
how a set of data is divided into parts.
The entire circle contains 100 of the data.
Each sector, or slice, of the circle represents
one part of the entire data set.
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Check It Out Example 1A
Use the circle graph to answer each question.
Which size car sold the most?
The sector for midsize cars is larger than any
other of the sectors of car sizes. This means
midsize cars were sold the most.
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Check It Out Example 1B
Use the circle graph to answer each question.
Approximately what percent of cars sold were
midsize?
The midsize sector is approximately half or about
50.
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Check It Out Example 1C
Use the circle graph to answer each question.
Which size sold lesslarge or small?
The smallest sector between Large and Small is
Large. Large sized cars sold less.
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Additional Example 2A Interpreting Circle Graphs
Leon surveyed 30 people about pet ownership. The
circle graph shows his results. Use the graph to
answer each question.
How many people own dogs only?
The circle graph shows that 20 of the 30 people
own dogs only.
20 of 30 0.2 30
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6 people own dogs only.
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Additional Example 2B Interpreting Circle Graphs
Leon surveyed 30 people about whether they own
pets. The circle graph shows his results. Use the
graph to answer each question.
How many people own both cats and dogs?
Since 20 is 6 people, 10 is 3 people. 3 people
own both cats and dogs.
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Check It Out Example 2A
Fifty students were asked which instrument they
could play. The circle graph shows the responses.
Use the graph to answer each question.
flute 10
How many students do not play an instrument?
drum 20
The circle graph shows that 50 of 50 students do
not play an instrument.
50 of 50 0.5 50
no instrument 50
piano 20
25
25 students do not play an instrument.
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Check It Out Example 2B
Fifty students were asked which instrument they
could play. The circle graph shows the responses.
Use the graph to answer each question.
flute 10
drum 20
Ten students said they play the piano. How many
play the flute?
Since 20 is 10 students, 10 is 5 students.
Five students play the flute.
no instrument 50
piano 20
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Additional Example 3A
Choosing an Appropriate Graph
Decide whether a bar graph or circle graph would
best display the information. Explain your answer.
the percent of U.S. population living in the
different states
A circle graph is the better choice because it
shows how parts of a whole are divided.
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Additional Example 3B
Choosing an Appropriate Graph
Decide whether a bar graph or circle graph would
best display the information. Explain your
answers.
the number of tickets sold for each night of a
school play
A bar graph is the better choice because it makes
it easy to see how the number of tickets sold
changed over each night.
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Additional Example 3C
Choosing an Appropriate Graph
Decide whether a bar graph or circle graph would
best display the information. Explain your
answers.
the comparison between the number of students in
a math class and the total student population.
A circle graph is the better choice because it
shows what part of the students are in a math
class.
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Check It Out Example 3A
Decide whether a bar graph or circle graph would
best display the information. Explain your
answers.
the percent of people buying a certain color of a
new vehicle
A circle graph is the better choice because it
makes it easier to see what part (or percent) of
people is buying a certain color of vehicle.
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Check It Out Example 3B
Decide whether a bar graph or circle graph would
best display the information. Explain your
answers.
the comparison of different themes voted on for a
school party
A circle graph is a better choice because the
sectors that represent the themes could be easily
compared.
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Check It Out Example 3C
Decide whether a bar graph or circle graph would
best display the information. Explain your
answers.
the number of visitors to the Grand Canyon for
the last ten years
A bar graph is the better choice because it makes
it easy to see how the number of visitors has
changed over the years.
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Lesson Quiz Part I
Use the circle graph to answer questions 1-4.
1. Which group of CDs sold the most? 2. What
percent of the CD sales are country? 3. Which
type of CD sells the least?
rock
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rap
4. If a total of 500 CDs are sold, how many are
Jazz?
55
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Lesson Quiz Part II
5. Would a bar or circle graph best display the
sales of a department store for the last 5 months?
bar graph