Course 2

Course 2

3-7 Fractions and Decimals

Today’s Plan:-Warm Up & Correct Homework-Write Fractions as Decimals-Write Decimals as Fractions

11/04/10 Equivalent Fractions and Decimals

Learning Target:

-I can write fractions as decimals and decimals as fractions.

Entry Task

1. Write as a mixed number.

2. Write 4 as an improper fraction.

3. A carpenter is building a stairway. Each stair has to be 12 in. wide. The carpenter’s ruler is marked in sixteenths. Write the length he should measure as inches and sixteenths of an inch.

17837

78

1416

12

317

182

in.

Note: We are in lesson 3-9 in the old book and lesson 2-10 in the new book.

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Correct Homework:

Page 168 #21-40

*Remember if you want to retake your math test, retakes are Monday after school.



Learning Target:


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Learning Target:


Write the fractions and decimal represented by models 1, 2,and 3. Each grid has 100 squares.

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Learning Target:


How do you convert a fraction to a decimal?

To convert a fraction to a decimal, divide the numerator by the denominator!

= 1 ÷ 8

0.125

18

Write each fraction as a decimal. Round to the nearest hundredth, if necessary.

Additional Example 1: Writing Fractions as Decimals

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2-10 Equivalent Fractions and Decimals

A. 14

5.000

B. 95 C. 5

3

314 = 0.25 9

5= 1.8

1

– 3

20

.6

– 1820

– 18

6

20– 18

2

53 ≈ 1.67

6

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The decimals 0.75 and 1.2 in Example 1 are terminating decimals because the decimals comes to an end. The decimal 0.333…is a repeating decimal because the decimal repeats a pattern forever. You can also write a repeating decimal with a bar over the repeating part.

0.333… = 0.3

0.8333… = 0.83

0.727272… = 0.72

Write each fraction as a decimal.

Use Mental Math to Write Fractions as Decimals

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A.

4 5

4 5

x 2 2

= 8 10

= 0.8

Multiply to get a power of ten in the denominator.

B.

37 50

37 50

x 2 2

= 74 100

= 0.74



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A.

3 5

3 5

x 2 2

= 6 10

= 0.6


B.

18 25

18 25

x 4 4

= 72 100

= 0.72


Write each decimal as a fraction in simplest form.

Additional Example 3: Writing Decimals as Fractions

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A. 0.018 B. 1.55

0.018 = 181,000 1.55 =

155100

=18 ÷ 2

1,000 ÷ 2=155 ÷ 5

100 ÷ 5

=3120

or 1 1120=

9500

You read the decimal 0.018 as “eighteen thousandths.”

Reading Math

Check It Out: Example 3

Insert Lesson Title Here

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A. 0.015 B. 1.30

0.015 = 151,000 1.30 =130

100

= 15 ÷ 51,000 ÷ 5

= 130 ÷ 10100 ÷ 10

= 1310

or 1 310

= 3200

A football player completed 1,546 of the 3,875 passes he attempted. Find his completion rate. Write your answer as a decimal rounded to the nearest thousandth.

Additional Example 4: Sports Application

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Fraction What the Calculator Shows Completion Rate

1,5463,875 1546 ÷ 3875 ENTER 0.398967742 0.399

His completion rate is 0.399.

Check It Out: Example 4


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Johnny Unitas, a former professional quarterback, completed 2,830 of the 5,186 passes he attempted. Find his completion rate. Write your answer as a decimal rounded to the nearest thousandth.

Fraction What the Calculator Shows Completion Rate

2,8305,186 2830 ÷ 5186 ENTER 0.54569996 0.546

His completion rate is 0.546.

Lesson Quiz


1.

3. 4.


5. 0.42

7. If your soccer team wins 21 out of 30 games,

what is your team’s winning rate?

2.6253.2


2150

69 8

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165 2.

218

6. 8.625

0.70

710

1120 0.550.7

5 8

or 8

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Assignment:

Page 172 #14-26

*Remember if you want to retake your math test, retakes are Monday after school.



Learning Target:


Course 2

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