Course: 7th Grade Math
Student Objective
(Obj. 5a, 5c) TSW… use percentages to interpret data represented in a circle graph.
DETAIL LESSON PLAN
Thursday, March 29 / Friday, March 30
Lesson
7-7 Circle Graphs (Textbook Pages: 354-559)
Extra Resources
None Today
Homework
N/A
Last Night’s Homework
N/A
Bellwork
Pass out student notes on circle graphs. Students will read the notes and attempt you-try problem numbers 1 and 2.
Prior Knowledge
 In the second nine weeks, we learned to find the percent of a number.
Anticipatory Set
 Today, we will continue our unit on Data Analysis. We will use what we have learned in the past about percentages to help us
interpret data represented in a circle graph… sometimes referred to as a pie chart!
 Why learn about circle graphs?
 Well, let’s look at a real world example…
 Show Tornados PowerPoint. (Percentages of category F1, F2, F3, F4, F5 tornados)
Teacher Input
 Pass out Student Notes.



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Discuss how to interpret data in a circle graph by finding the percent of a number.
Review answer to bellwork problem #1.
Discuss how to determine the angle measure of each section on a circle graph.
Review answer to bellwork problem #2.
Have students work you-try problem.

Have students work the College Preference activity.
Assessment
Observation and questioning. Also, major test next class.
Closure
Today we talked about a circle graph which we learned is another way to analyze data.
1. How many degrees are in a circle? 360°
2. How do you determine the angle measure of each section of a circle graph?
You take the percent of each section, change it to a decimal, and then multiply that number by 360°.
3. Now, once again… how do find the percent of a number?
Change the percent to a decimal, then multiply it by the number they give you.
4. Why do I have to change the percent to a decimal first?
Well, the calculator will not accept the % symbol. We much convert the percent to a decimal by moving the decimal two places
to the right then we may enter that number in our calculator.
Student Notes
Lesson 7-7 Circle Graphs
Textbook Pages 354-359
Circle Graphs
A circle graph is a graph that represents parts of a whole. The SUM of all the parts must equal 100%.
We can use what we’ve learned about calculating the percent of a number to help us analyze important
information in a circle graph.
The National Weather Service documents that about 1,000 tornados touchdown each
year in the United States.
Tornados
Weak (F0 - F1)
Strong (F2 - F3)
Violent (F4 - F5)
1% Violent
25%
Strong
74%
Weak
Directions: Fill in the missing numbers for violent tornados.
1) Of the 1,000 tornados that touched down, how many were actually weak, strong, and violent?
Weak
Strong
74%  .74
25%  .25
.74
.25
Violent
___%  ____
____
1000 =
1000 =
____ =
Answer:
Answer:
740
250
Answer: _____
Total
1,000
2) How do you determine the angle measure of each section?
Every circle has 360 . Therefore, the sum of all our angle measurements must equal to 360 .
To find the Angle Measurements of each section of a circle graph follow these steps:
Weak
Strong
74%  .74
25%  .25
.74
.25
360 =
360 =
Answer:
Answer:
266.4
90
Violent
___%  ____
___
____ =
Answer:
______
Total
360
Student Notes
(Answer Key)
Lesson 7-7 Circle Graphs
Textbook Pages 354-359
Circle Graphs
A circle graph is a graph that represents parts of a whole. The SUM of all the parts must equal 100%.
We can use what we’ve learned about calculating the percent of a number to help us analyze important
information in a circle graph.
The National Weather Service documents that about 1,000 tornados touchdown each
year in the United States.
Tornados
Weak (F0 - F1)
Strong (F2 - F3)
Violent (F4 - F5)
1% Violent
25%
Strong
74%
Weak
Directions: Fill in the missing numbers for violent tornados.
1) Of the 1,000 tornados that touched down, how many were actually weak, strong, and violent?
Weak
Strong
Violent
74%  .74
25%  .25
.74
.25
1000 =
1000 =
Answer:
Answer:
740
250
1%  .01
.01
1000 =
Answer:
10
Total
1,000
2) How do you determine the angle measure of each section?
Every circle has 360 . Therefore, the sum of all our angle measurements must equal to 360 .
To find the Angle Measurements of each section of a circle graph follow these steps:
Weak
Strong
Violent
74%  .74
25%  .25
.74
.25
360 =
360 =
Answer:
Answer:
266.4
90
1%  .01
.01
360 =
Answer:
3.6
Total
360
Name: ____________________________
Date: _________________
Period: ____________
Brian’s high school surveyed 250 graduating seniors about what college they
planned to attend. His results are shown in the circle graph.
College Preference
Delta State
14%
Other
12%
Jackson State
18%
Ole Miss
30%
Mississippi State
26%
1) How many students plan to attend Jackson State (.18 x 250):
_________________
What is the angle measurement of the Jackson State section (.18 x 360º): _________________º
2) How many students plan to attend Mississippi State:
What is the angle measurement of the Mississippi State section:
_________________
_________________º
3) How many students plan to attend Ole Miss:
What is the angle measurement of the Ole Miss section:
_________________
_________________º
4) How many students plan to attend Delta State:
What is the angle measurement of the Delta State:
_________________
_________________º
5) How many students plan to attend Other Colleges:
What is the angle measurement of the Other Colleges:
_________________
_________________º
Name: Answer Key
Date: _________________
Period: ____________
Brian’s high school surveyed 250 graduating seniors about what college they
planned to attend. His results are shown in the circle graph.
College Preference
Delta State
14%
Other
12%
Jackson State
18%
Ole Miss
30%
Mississippi State
26%
1) How many students plan to attend Jackson State (.18 x 250):
What is the angle measurement of the Jackson State section (.18 x 360º):
45
64.8º
2) How many students plan to attend Mississippi State:
What is the angle measurement of the Mississippi State section:
65
93.6º
3) How many students plan to attend Ole Miss:
What is the angle measurement of the Ole Miss section:
75
108º
4) How many students plan to attend Delta State:
What is the angle measurement of the Delta State:
35
50.4º
5) How many students plan to attend Other Colleges:
What is the angle measurement of the Other Colleges:
30
43.2º