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

2 8.1 Ratio In this section, you will learn about Ratios Rates Unit rates Unit costs

3 Real-life ratios

4 Ratios

5 EXAMPLE 2 Carry-on luggage. Airlines allow passengers to carry a piece of luggage onto an airplane only if it will fit in the space shown in Figure 8-1. What is the ratio of the length of the space to its width?

6 Rates

7

8 Unit rates

9 Computing gas mileage

10 Unit costs

11 EXAMPLE 7 Comparison shopping. Olives come packaged in a 10-ounce jar, which sells for $2.49, or in a 6-ounce jar, which sells for $1.53. (See Figure 8-3.) Which is the better buy?

Proportions In this section, you will learn about Proportions Means and extremes of a proportion Solving proportions Writing proportions to solve problems

13 Ladders - the 4-to-1 rule

14 Proportions

15 Means and extremes of a proportion

16 Means and extremes of a proportion

17 Solving proportions

18 Solving proportions with a calculator

19 Writing proportions to solve problems EXAMPLE 6 Grocery shopping. If 5 apples cost $1.15, how much will 16 apples cost?

20 EXAMPLE 7 Scale drawing. A scale is a ratio (or rate) that compares the size of a model, drawing, or map to the size of an actual object. On the next page, the airplane in Figure 8-5 is drawn using a scale of 1 inch: 6 feet. This means that 1 inch on the drawing is actually 6 feet on the plane. The distance from wing tip to wing tip (the wingspan) on the drawing is 5 inches. What is the actual wingspan of the plane?

21 EXAMPLE 7 Scale drawing.

American Units of Measurement In this section, you will learn about American units of length Converting units of length American units of weight American units of capacity Units of time

23 American units of length

24 EXAMPLE 1 Measuring the length of a nail. To the nearest ¼ inch, find the length of the nail in Figure 8-7.

25 EXAMPLE 2 Measuring the length of a paper clip. To the nearest ⅛ inch, find the length of the paper clip in Figure 8-8.

26 EXAMPLE 3 Measuring the length of a ticket. Find the length of the tear-off part of the concert ticket in Figure 8-9.

27 Converting units of length

28 Finding the length of a football field in miles

29 American units of weight

30 Finding the weight of a car in pounds

31 American units of capacity

32 Units of time

33 EXAMPLE 9 Astronomy. A lunar eclipse occurs when the Earth is between the sun and the moon in such a way that the Earth’s shadow darkens the moon. See Figure 8-10 (which is not to scale). A total lunar eclipse can last as long as 105 minutes. How many hours is this?

Metric Units of Measurement In this section, you will learn about Metric units of length Converting units of length Metric units of mass Metric units of capacity Cubic centimeters

35 Metric units of length

36 Metric ruler

37 EXAMPLE 1 Measuring the length of a nail. To the nearest centimeter, find the length of the nail in Figure 8-13.

38 EXAMPLE 2 Measuring the length of a paper clip. To the nearest ⅛ inch, find the length of the paper clip in Figure 8-8.

39 EXAMPLE 2 Measuring the length of a paper clip. To the nearest millimeter, find the length of the paper clip in Figure 8-8.

40 Converting units of length

41 Converting units of length

42 Metric units of mass

43 Metric units of capacity

44 Metric units of capacity

45 Cubic centimeters 1 mL = 1 cm 3 = 1 cc 5 cc = 5 mL 1,000 cc = 1,000 mL = 1 liter

Converting between American and Metric Units In this section, you will learn about Converting between American and metric units Comparing American and metric units of temperature

47 Converting between American and metric units

48 EXAMPLE 1 Clothing label. Figure 8-17 shows a label sewn into some pants made in Mexico for sale in the United States. Express the waist size to the nearest inch.

49 Equivalent Weights and Masses

50 Equivalent Capacities

51 Comparing American and metric units of temperature

52 Conversion formulas for temperature