1 Alan S. Tussy R. David Gustafson Prealgebra Second Edition Copyright © 2002 Wadsworth Group.

2 5.1 An Introduction to Decimals In this section, you will learn about Decimals The place value system for decimal numbers Reading and writing decimals Comparing decimals Rounding

3 Decimal numeration system

4 Decimals

5 The place value system

6

7 Reading and writing decimals

8 Comparing decimals

9 EXAMPLE 4 Graphing decimals.

10 Rounding a decimal

11 Rounding

Addition and Subtraction with Decimals In this section, you will learn about Adding decimals Subtracting decimals Adding and subtracting signed decimals

13 Federal income tax forms

14 Adding decimals

15 Preventing heart attacks

16 Subtracting decimals

17 EXAMPLE 3 Conditioning program. A 350-pound football player lost 15.7 pounds during the first week of practice. During the second week, he gained 4.9 pounds. What is his weight after the first two weeks of practice?

18 Weather balloons

19 Adding and subtracting signed decimals

Multiplication with Decimals In this section, you will learn about Multiplying decimals Multiplying decimals by powers of 10 Multiplying signed decimals Order of operations

21 Multiplying decimals

22 Multiplying decimals

23 Heating costs

24 Multiplying decimals - powers of 10

25 Multiplying by a power of 10

26 EXAMPLE 5 Tachometer. A tachometer indicates the engine speed of a vehicle, in revolutions per minute (rpm). What engine speed is indicated by the tachometer in Figure 5-6?

27 EXAMPLE 10 Weekly earnings. A cashier’s work week is 40 hours. After his daily shift is over, he can work overtime at a rate 1.5 times his regular rate of $7.50 per hour. How much money will he earn in a week if he works 6 hours of overtime?

Division with Decimals In this section, you will learn about Dividing a decimal by a whole number Divisors that are decimals Rounding when dividing Dividing decimals by powers of 10 Order of operations Statistics problems

29 Dividing a decimal by a whole number

30 Dividing a decimal by a whole number

31 Dividing a decimal by a whole number

32 Divisors that are decimals

33 Division with a decimal divisor

34 The nucleus of a cell

35 Dividing decimals by powers of 10

36 Dividing a decimal by a power of 10

37 Statistics problems

38 EXAMPLE 7 Machinist’s tools. The diameters (distances across) of eight stainless steel bearings were found using the vernier calipers shown in Figure 5-7. Find a. the mean, b. the median, and c. the mode of the set of measurements listed below cm, 3.25 cm, 3.48 cm, 3.39 cm, 3.54 cm, 3.48 cm, 3.23 cm, 3.24 cm

Fractions and Decimals In this section, you will learn about Writing fractions as equivalent decimals Repeating decimals Rounding repeating decimals Graphing fractions and decimals Problems involving fractions and decimals

40 Writing fractions as equivalent decimals

41 Rounding repeating decimals - ⅓

42 The fixed-point key

43 Graphing fractions and decimals

44 EXAMPLE 9 Shopping. During a trip to the grocery store, a shopper purchased ¾ pound of fruit, priced at $0.88 a pound, and ⅓ pound of fresh-ground coffee, selling for $6.60 a pound. Find the total cost of these items.

Solving Equations Containing Decimals In this section, you will learn about Solving equations using the properties of equality Simplifying expressions to solve equations Problem solving with equations

46 Strategy for solving equations

47 EXAMPLE 9 Business expenses. A business decides to rent a copy machine (Figure 5-10) instead of buying one. Under the rental agreement, the company is charged $65 per month plus 2¢ for every copy made. If the business has budgeted $125 for copier expenses each month, how many copies can be made before exceeding the budget?

Square Roots In this section, you will learn about Square roots Evaluating numerical expressions containing radicals Square roots of fractions and decimals Using a calculator to find square roots Approximating square roots

49 Square root

50 Finding a square root

51 THE REAL NUMBERS