1. 7.2
Rates
How do you use rates to compare quantities?

2. Texas Essential Knowledge and Skills
The student is expected to:
Proportionality—6.4.D
Give examples of rates as the comparison by division of
two quantities having different attributes, including rates
as quotients.
Mathematical Processes
6.1.G
Display, explain, and justify mathematical ideas and arguments using precise mathematical language in written or oral communication.

3. ADDITIONAL EXAMPLE 1 A
The cost of 3 candles is $ What is the unit price?
$6.50 per candle B
Michael walks 30 meters in 20 seconds. How many meters does he walk per second?
1.5 meters per second C
An airplane makes a 2,748-mile flight in 6 hours. What is the airplane’s average rate of speed in miles per hour?
458 miles per hour

4. ADDITIONAL EXAMPLE 2
In a youth soccer league, each team will have 18 players and 3 coaches. This year 162 players signed up. How many coaches are needed?
27 coaches

5. 7.2 LESSON QUIZ
6.4.D
The table shows the available sizes and prices of Henry’s favorite movie popcorn. Use the table to answer questions 1 and 2. 1.
What is the unit rate for each size?
regular: 0.50; large: 0.47

6. The table shows the available sizes and prices of Henry’s favorite movie popcorn. Use the table to answer questions 1 and 2. 2.
Which size is the better buy?
large

7. The table shows the available sizes and prices of Henry’s favorite movie popcorn. Use the table to answer questions 1 and 2. 3.
Rita charges $60 for 5 tutoring sessions. What is the cost per session?
$12

8. The table shows the available sizes and prices of Henry’s favorite movie popcorn. Use the table to answer questions 1 and 2. 4.
A package of 12 pens costs $3.60. What is the cost per pen?
$0.30

9. The table shows the available sizes and prices of Henry’s favorite movie popcorn. Use the table to answer questions 1 and 2. 5.
A train travels 40 miles in 65 minutes. To the nearest tenth of a mile, how far does the train travel per minute?
0.62 mile

10. second carpenter; 3 windows per hour
A carpenter installed 10 windows in 4 hours. A second carpenter installed 15 windows in 5 hours. A third carpenter installed 50 windows in 20 hours.
• Draw a 4-column rate table to display this information. Include a column for Unit Rate on the table.
• Which carpenter is working at the fastest rate?
second carpenter; 3 windows per hour

11. • Who has the next fastest rate? Explain.
The first and the third carpenters are tied for the next fastest rate–2.5 windows per hour.

12. How do you use rates to compare quantities?
Sample answer:
You use division to compare two quantities with different units.