Working with Percents

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Working with Percents
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Understanding Percents
Per out of Cent one hundred Put them
together and the word percent means out of
one hundred
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Percents Proportions
Since we know percents are out of 100 it is easy
to set up a proportion to help us solve percent
problems
or
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Example 1
75 of 40 is what number?
x
75
40
5
Example 2
30 of 60 is what number?
x
30
60
6
Example 3
14 of 88 is what number?
x
14
88
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Example 4
31 is what percent of 124?
31
x
124
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Example 5
6 is what percent of 400?
6
x
400
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Example 6
102.9 is what percent of 105?
102.9
x
105
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Example 7
30 is 75 of what number?
30
75
x
11
Example 8
156 is 65 of what number?
156
65
x
12
Example 9
12 is 1.5 of what number?
12
1.5
x
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Percent Word Problems

• Determine what information you already have
• What is the part?
• What is the whole?
• What is the percent?
• Plug into the proportion
• Cross multiply to solve
• Label your answer

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Example 1
Heather is downloading a song from iTunes. The
song she is downloading will take 40 seconds to
complete. So far it is 75 of the way to
completion. How long has she been waiting so far?
What is the part? What is the whole? What is
the percent?
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Example 2
Josephine recently took a test in her Science
class. She earned 11 out of 16 possible points.
What percent did she earn?
What is the part? What is the whole? What is
the percent?
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Example 3
Mrs. Padmanabha likes to bake for the teachers
on Team Galileo. Last week, the teachers ate 9 of
the cupcakes Mrs. Padmanabha made. If that was
60 of the cupcakes, how many cupcakes did Mrs.
Padmanabha make?
What is the part? What is the whole? What is
the percent?