# 1.8E: Exercises

- Page ID
- 30097

## Practice Makes Perfect

Needs to be integrated from https://cnx.org/contents/CImQfPDv@8.46:NciJ1qa0@19/1-7-Decimals

**Name and Write Decimals**

In the following exercises, write as a decimal.

__531__.

Twenty-nine and eighty-one hundredths

532.Sixty-one and seventy-four hundredths

__533__.

Seven tenths

534.Six tenths

__535__.

Twenty-nine thousandth

536.Thirty-five thousandths

__537__.

Negative eleven and nine ten-thousandths

538.Negative fifty-nine and two ten-thousandths

In the following exercises, name each decimal.

__539__.

5.5

540.14.02

__541__.

8.71

542.2.64

__543__.

0.002

544.0.479

__545__.

−17.9−17.9

546.−31.4−31.4

**Round Decimals**

In the following exercises, round each number to the nearest tenth.

__547__.

0.67

548.0.49

__549__.

2.84

550.4.63

In the following exercises, round each number to the nearest hundredth.

__551__.

0.845

552.0.761

__553__.

0.299

554.0.697

__555__.

4.098

556.7.096

In the following exercises, round each number to the nearest ⓐ hundredth ⓑ tenth ⓒ whole number.

__557__.

5.781

558.1.6381

__559__.

63.479

560.84.28184.281

**Add and Subtract Decimals**

In the following exercises, add or subtract.

__561__.

16.92+7.5616.92+7.56

562.248.25−91.29248.25−91.29

__563__.

21.76−30.9921.76−30.99

564.38.6+13.6738.6+13.67

__565__.

−16.53−24.38−16.53−24.38

566.−19.47−32.58−19.47−32.58

__567__.

−38.69+31.47−38.69+31.47

568.29.83+19.7629.83+19.76

__569__.

72.5−10072.5−100

570.86.2−10086.2−100

__571__.

15+0.7315+0.73

572.27+0.8727+0.87

__573__.

91.95−(−10.462)91.95−(−10.462)

574.94.69−(−12.678)94.69−(−12.678)

__575__.

55.01−3.755.01−3.7

576.59.08−4.659.08−4.6

__577__.

2.51−7.42.51−7.4

578.3.84−6.13.84−6.1

**Multiply and Divide Decimals**

In the following exercises, multiply.

__579__.

(0.24)(0.6)(0.24)(0.6)

580.(0.81)(0.3)(0.81)(0.3)

__581__.

(5.9)(7.12)(5.9)(7.12)

582.(2.3)(9.41)(2.3)(9.41)

__583__.

(−4.3)(2.71)(−4.3)(2.71)

584.(−8.5)(1.69)(−8.5)(1.69)

__585__.

(−5.18)(−65.23)(−5.18)(−65.23)

586.(−9.16)(−68.34)(−9.16)(−68.34)

__587__.

(0.06)(21.75)(0.06)(21.75)

588.(0.08)(52.45)(0.08)(52.45)

__589__.

(9.24)(10)(9.24)(10)

590.(6.531)(10)(6.531)(10)

__591__.

(55.2)(1000)(55.2)(1000)

592.(99.4)(1000)(99.4)(1000)

In the following exercises, divide.

__593__.

4.75÷254.75÷25

594.12.04÷4312.04÷43

__595__.

$117.25÷48$117.25÷48

596.$109.24÷36$109.24÷36

__597__.

0.6÷0.20.6÷0.2

598.0.8÷0.40.8÷0.4

__599__.

1.44÷(−0.3)1.44÷(−0.3)

600.1.25÷(−0.5)1.25÷(−0.5)

__601__.

−1.75÷(−0.05)−1.75÷(−0.05)

602.−1.15÷(−0.05)−1.15÷(−0.05)

__603__.

5.2÷2.55.2÷2.5

604.6.5÷3.256.5÷3.25

__605__.

11÷0.5511÷0.55

606.14÷0.3514÷0.35

**Convert Decimals, Fractions and Percents**

In the following exercises, write each decimal as a fraction.

__607__.

0.04

608.0.19

__609__.

0.52

610.0.78

__611__.

1.25

612.1.35

__613__.

0.375

614.0.464

__615__.

0.095

616.0.085

In the following exercises, convert each fraction to a decimal.

__617__.

17201720

618.13201320

__619__.

114114

620.174174

__621__.

−31025−31025

622.−28425−28425

__623__.

15111511

624.18111811

__625__.

1511115111

626.2511125111

__627__.

2.4+582.4+58

628.3.9+9203.9+920

In the following exercises, convert each percent to a decimal.

__629__.

1%

630.2%

__631__.

63%

632.71%

__633__.

150%

634.250%

__635__.

21.4%

636.39.3%

__637__.

7.8%

638.6.4%

In the following exercises, convert each decimal to a percent.

__639__.

0.01

640.0.03

__641__.

1.35

642.1.56

__643__.

3

644.4

__645__.

0.0875

646.0.0625

__647__.

2.254

648.2.317

### Everyday Math

__649__.

**Salary Increase** Danny got a raise and now makes $58,965.95 a year. Round this number to the nearest

ⓐ dollar

ⓑ thousand dollars

ⓒ ten thousand dollars.

**New Car Purchase** Selena’s new car cost $23,795.95. Round this number to the nearest

ⓐ dollar

ⓑ thousand dollars

ⓒ ten thousand dollars.

__651__.

**Sales Tax** Hyo Jin lives in San Diego. She bought a refrigerator for $1,624.99 and when the clerk calculated the sales tax it came out to exactly $142.186625. Round the sales tax to the nearest

ⓐ penny and

ⓑ dollar.

**Sales Tax** Jennifer bought a $1,038.99 dining room set for her home in Cincinnati. She calculated the sales tax to be exactly $67.53435. Round the sales tax to the nearest

ⓐ penny and

ⓑ dollar.

__653__.

**Paycheck** Annie has two jobs. She gets paid $14.04 per hour for tutoring at City College and $8.75 per hour at a coffee shop. Last week she tutored for 8 hours and worked at the coffee shop for 15 hours.

ⓐ How much did she earn?

ⓑ If she had worked all 23 hours as a tutor instead of working both jobs, how much more would she have earned?

**Paycheck** Jake has two jobs. He gets paid $7.95 per hour at the college cafeteria and $20.25 at the art gallery. Last week he worked 12 hours at the cafeteria and 5 hours at the art gallery.

ⓐ How much did he earn?

ⓑ If he had worked all 17 hours at the art gallery instead of working both jobs, how much more would he have earned?

### Writing Exercises

__655__.

How does knowing about US money help you learn about decimals?

656.Explain how you write “three and nine hundredths” as a decimal.

__657__.

Without solving the problem “44 is 80% of what number” think about what the solution might be. Should it be a number that is greater than 44 or less than 44? Explain your reasoning.

658.When the Szetos sold their home, the selling price was 500% of what they had paid for the house 30 years ago. Explain what 500% means in this context.

### Self Check

ⓐ After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.

ⓑ What does this checklist tell you about your mastery of this section? What steps will you take to improve?