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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall.

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Fractions and Decimals

Martin-Gay, Basic Mathematics, 4e 22


Writing Fractions as Decimal

Writing Fractions as DecimalsTo write a fractions as a decimal, divide the numerator by the denominator.



Example

Write as a decimal.

0.2 5 1.0

10

0

1

5

11 5

5

1

5Thus, written as a decimal is 0.2.



Writing Fractions as Decimals

Practice Problem 1aPractice Problem 1a

SOLUTIONSOLUTION

Write as a decimal.5

2

5

2 25

0

020

4.

200

0.

P 298




Problem Practice 1bProblem Practice 1b

SOLUTIONSOLUTION

Write as a decimal.40

9

40

9 940

0

090

2.

80100

0. 02

80200

P 298

05

200 0



Example

Write as a decimal. 0.33

3 1.00

- 9

0

- 9

1

1

1

3

11 3

3

Notice that the digit 1 keeps occurring as the remainder. This will continue the digit 3 repeating in the quotient. We place a bar over the digit to indicate it repeats. 1

0.333

Should be

3.03

1

P 298

Martin-Gay, Basic Mathematics, 4ed 77

Practice Problems

P 298

00.56

Practice Problem 2a

decimal a as 6

5 Write

000.56

833.0

30.8or 833.0



Practice Problems

P 298

00.29

Practice Problem 2b

decimal a as 9

2 Write

00.29

22.0

20.or 22.0



Practice Problems

P 300

0000.2813

Practice Problem 3

ousandth.nearest th theto

Round decimal. a as 13

28 Write

0000.2813

1538.2

2.154 toRound



Practice Problems

P 299

0000.5316

Practice Problem 4

decimal. a as 16

53 Write

0000.5316

3125.3

3.3125

16

53

16

53




Example

Write as a decimal. 3

48

8 3.000

24

60

56

40

40

0

0.375

Write the fractional part only as a decimal.

34 4.375

8

Option 1. Option 2.

Write as an improper fraction and divide.

35

8

8 35.000

32

30

24

60

56

40

56

0

4.375

34 4.375

8


Practice Problems

P 300

0.35

Practice Problem 5

decimal. a as 5

3 Write

0.35

6.0

0.6



Practice Problems

P 300

0.350

Practice Problem 6

decimal. a as 50

3 Write

00.350

06.0

0.06




Comparing Fractions and Decimals

Original numbers

Decimals

Compare

100

9

0.09

0.0932

0.0932

0.09 0.0932

Thus 9

0.0932.100



Comparing Decimals and Fractions

Original numbers

Decimals

Compare

5

125.

25.020.0

Thus 5

1 25.

P 300

Practice Problem 7

.25 20.




Original numbers

Decimals

Compare

2

154.

54.050.0

P 300

Practice Problem 8a

Original numbers

Decimals

Compare

4.9

4

444.0or 4.444.0

Practice Problem 8b

Original numbers

Decimals

Compare

7

572.

72.07142.0

Practice Problem 8c

.54 50.

.72 71.




Original numbers

Decimals

Sort

3

1302.

302.03.0

P 300

Practice Problem 9a

Practice Problem 9b

Practice Problem 9c

302.

8

3

375.0

3. 375.

Original numbers

Decimals

Sort

26.14

11

25.126.1

1.25

5

21

4.1

26.1 4.1

Original numbers

Decimals

Sort

4.0 41.0

41.04.0

4.

7

5

7142.0

41. 7142.



Solving Area Problems Containing Fractions and Decimals

EXAMPLEEXAMPLE

SOLUTIONSOLUTION

The area of a triangle is

height.base2

1 Area

Find the area of the following triangle.

17 feet

4.4 feet

4.4712

1 Area

)4.4)(7.5(1 Write as .5.2

1

ft sq 7.43



DONE



Example

The area of a triangle is

height.base2

1 Area

Find the area of the following triangle.

17 feet

4.4 feet1

Area 17 4.42

0.5 17 4.4

ft sq 7.43

The area of the triangle is 37.4 square feet.

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