1. Ratios, Rates, and Unit Rates 5-2 Warm Up Divide. Round answers to the nearest tenth. 1. 2. 3. 4. 23.3 3.5 23.8 23.9 420 18 73 21 380 16 430 18

2. Ratios, Rates, and Unit Rates 5-2 Learn to work with rates and ratios.

3. Ratios, Rates, and Unit Rates 5-2 Ratio: 90 3 Rate: 90 miles 3 hours Read as “90 miles per 3 hours.” A rate is a comparison of two quantities that have different units.

4. Ratios, Rates, and Unit Rates 5-2 Unit rates are rates in which the second quantity is 1. unit rate: 30 miles, 1 hour or 30 mi/h The ratio 90 3 can be simplified by dividing: 90 3 = 30 1

5. Ratios, Rates, and Unit Rates 5-2 Additional Example 1: Finding Unit Rates Geoff can type 30 words in half a minute. How many words can he type in 1 minute? Write a rate. = Geoff can type 60 words in one minute. Multiply to find words per minute. 60 words 1 minute 30 words minute 1212 30 words 2 minute 2 1212

6. Ratios, Rates, and Unit Rates 5-2 Check It Out: Example 1 Penelope can type 90 words in 2 minutes. How many words can she type in 1 minute? 90 words 2 minutes Write a rate. = Penelope can type 45 words in one minute. 90 words ÷ 2 2 minutes ÷ 2 Divide to find words per minute. 45 words 1 minute

7. Ratios, Rates, and Unit Rates 5-2 Unit price is a unit rate used to compare price per item.

8. Ratios, Rates, and Unit Rates 5-2 Jamie can buy a 15-oz jar of peanut butter for $2.19 or a 20-oz jar for $2.78. Which is the better buy? Additional Example 4: Finding Unit Prices to Compare Costs  $2.19 15 = $0.15 = $2.78 20  $0.14 The better buy is the 20-oz jar for $2.78. price for jar number of ounces price for jar number of ounces Divide the price by the number of ounces.

9. Ratios, Rates, and Unit Rates 5-2 Golf balls can be purchased in a 3-pack for $4.95 or a 12-pack for $18.95. Which is the better buy? Check It Out: Example 4 Divide the price by the number of balls. price for package number of balls  $4.95 3 =$1.65 price for package number of balls = $18.95 12  $1.58 The better buy is the 12-pack for $18.95.

10. Ratios, Rates, and Unit Rates 5-2 Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

11. Ratios, Rates, and Unit Rates 5-2 Lesson Quiz: Part I 1. Meka can make 6 bracelets per half hour. How many bracelets can she make in 1 hour? 2. A penny has a mass of 2.5 g and a volume of approximately 0.360 cm 3. What is the approximate density of a penny? 3. Melissa is driving to her grandmother's house. In the first 3 hours of the drive, she travels 159 miles. What is Melissa's average speed? ≈ 6.94 g/cm 3 53 mi/h 12

12. Ratios, Rates, and Unit Rates 5-2 Lesson Quiz: Part II Determine the better buy. 5. A half dozen carnations for $4.75 or a dozen for $9.24 a dozen

13. Ratios, Rates, and Unit Rates 5-2 1. John can walk 16 miles in 4 hours. How many miles can he walk in one hour? A. 16 miles B. 8 miles C. 4 miles D. 2 miles Lesson Quiz for Student Response Systems

14. Ratios, Rates, and Unit Rates 5-2 2. Estimate the unit rate. 272 sailors in 17 ships A. 12 sailors per ship B. 14 sailors per ship C. 16 sailors per ship D. 18 sailors per ship Lesson Quiz for Student Response Systems

15. Ratios, Rates, and Unit Rates 5-2 3. Which of the following would be a better buy than purchasing 4 mangoes for $16? A. 2 mangoes for $10 B. half a dozen mangoes for $25 C. 8 mangoes for $ 28 D. one dozen mangoes for $54 Lesson Quiz for Student Response Systems