Warm Up

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Warm Up
Problem of the Day
Lesson Presentation
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Warm Up Write each fraction as a decimal. 1.
2. Write each decimal as a fraction. 3.
0.375 4. 0.05
0.9
0.75
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Problem of the Day Wally wanted to change the
scale of a drawing from 1 in. 2 ft to 1 in.
10 ft. The scale height of a building in the
first drawing is 25 in. How high is the building
in the new drawing?
5 in.
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Learn to write percents as decimals and as
fractions.
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Vocabulary
percent
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Most states charge sales tax on items you
purchase. Sales tax is a percent of the items
price. A percent is a ratio of a number to
100. You can remember that percent means per
hundred. For example, 8 means 8 per hundred,
or 8 out of 100.
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• If a sales tax rate is 8, the following
  statements are true
• For every 1.00 you spend, you pay 0.08 in
  sales tax.
• For every 10.00 you spend, you pay 0.80 in
  sales tax.
• For every 100 you spend, you pay 8 in sales
  tax.

Because percent means per hundred, 100 means
100 out of 100. This is why 100 is often used
to mean all or the whole thing.
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Additional Example 1 Modeling Percent Use a
10-by-10-square grid to model 17.
A 10-by-10 square grid has 100 squares.
17 means 17 out of 100 or .
Shade 17 squares out of 100 squares.
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Check It Out Example 1 Use a 10-by-10-square
grid to model 26.
A 10-by-10 square grid has 100 squares.
26 means 26 out of 100 or .
Shade 26 squares out of 100 squares.
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Additional Example 2 Writing Percents as
Fractions Write 35 as a fraction in simplest
form.
Write the percent as a fraction with a
denominator of 100.
35

Write the fraction in simplest form.
Written as a fraction, 35 is .
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Check It Out Example 2 Write 65 as a fraction
in simplest form.
Write the percent as a fraction with a
denominator of 100.
65

Write the fraction in simplest form.
Written as a fraction, 65 is .
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Additional Example 3 Life Science
Application Janell has 20 body fat. Write 20
as a fraction in simplest form.
Write the percent as a fraction with a
denominator of 100.
20

Write the fraction in simplest form.
Written as a fraction, 20 is .
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Check It Out Example 3 Timmy has 14 body fat.
Write 14 as a fraction in simplest form .
Write the percent as a fraction with a
denominator of 100.
14

Write the fraction in simplest form.
Written as a fraction, 14 is .
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Additional Example 4 Writing Percents as
Decimals Write 56 as a decimal.
Write the percent as a fraction with a
denominator of 100.
56
Write the fraction as a decimal.
Written as a decimal, 56 is 0.56.
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Check It Out Example 4 Write 32 as a decimal.
Write the percent as a fraction with a
denominator of 100.
32
Write the fraction as a decimal.
Written as a decimal, 32 is 0.32.
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Additional Example 5 Application Water made up
85 of the fluids that Kirk drank yesterday.
Write 85 as a decimal.
Write the percent as a fraction with a
denominator of 100.
85
85 100 0.85
Write the fraction as a decimal.
Written as a decimal, 85 is 0.85.
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Check It Out Example 5 Water made up 95 of the
fluids that Lisa drank yesterday. Write 95 as a
decimal.
Write the percent as a fraction with a
denominator of 100.
95
95 100 0.95
Write the fraction as a decimal.
Written as a decimal, 95 is 0.95.
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Lesson Quiz
Write each percent as a fraction in simplest
form. 1. 52 2. 29 Write each percent as a
decimal. 3. 17 4. 86 5. A store clerk has an
8 sales increase. Write the increase as a
fraction in simplest form and as a decimal.
0.17
0.86
, 0.08