1.8E: Exercises

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Jan 6, 2020
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- 1.8: Decimals
- 1.9: The Real Numbers

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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.

630.

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.

644.

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.

650.

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.

652.

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?

654.

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.

$This is a table that has six rows and four columns. In the first row, which is a header row, the cells read from left to right “I can…,” “Confidently,” “With some help,” and “No-I don’t get it!” The first column below “I can…” reads “name and write decimals,” “round decimals,” “add and subtract decimals,” “multiply and divide decimals,” and “convert decimals, fractions and percents.” The rest of the cells are blank.$

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

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