8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 1 of 4)
Travis just got a new car for his 16th birthday with the condition that he would pay for all of
his gasoline. Since he has this responsibility he’s always interested in getting the best deal
at the filling station. Travis’ brother Matthew said he paid $42.50 for 17 gallons of gasoline
at Mitchell’s Fill-Up Station. Travis’ girlfriend Hailee paid $42.00 for 15 gallons at The
Guzzler Fill-Up Station. Where would you suggest Travis go for the best deal?
1. What are the two quantities being compared?
2. What are the rates for Matthew’s purchase and Hailee’s purchase?
3. How much did Matthew pay for each gallon? How much did Hailee pay per gallon? Justify your
response. Write the two unit rates.
4. Who got the better deal—Matthew or Hailee? Why?
5. How much does seven gallons of gas cost at The Guzzler Fill-Up Station? Explain your
solution.
6. How much gasoline could Travis get at Mitchell’s Fill-Up Station if he had $25.00? Round
answers to the nearest tenth. Explain your solution.
©2010, TESCCC
08/01/10
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 2 of 4)
7. Complete the table and graph below:
Mitchell’s Fill-Up Station
# of Gallons
Process
Cost
1
17
©2010, TESCCC
08/01/10
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 3 of 4)
8. Complete the table and graph below:
# of Gallons
1
The Guzzler
Process
15
©2010, TESCCC
08/01/10
Cost
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 4 of 4)
Use the table and graph for The Guzzler Fill-Up Station to help check the reasonableness of
your answers to the following questions.
9. What does the point (3, 8.40) represent?
10. What does the point (10, 28) represent?
11. What is the ordered pair that represents the unit rate?
12. If Hailee spent $33.60, how many gallons of gas did she purchase?
13. If Hailee bought 8 gallons of gas, how much did she spend?
In questions 14 – 15, you will compare the data in the tables for Mitchell’s Fill-Up Station
with the data for The Guzzler Fill-Up Station.
14. What is the same about the data in the tables?
15. What is different about the data in the tables?
In questions 16 – 17, you will compare the data in the graphs for Mitchell’s Fill-Up Station
with the data for The Guzzler Fill-Up Station.
16. What is the same about the data in the graphs?
17. What is different about the data in the graphs?
©2010, TESCCC
08/01/10
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 1 of 4) KEY
Travis just got a new car for his 16th birthday with the condition that he would pay for all of
his gasoline. Since he has this responsibility, he’s always interested in getting the best deal
at the filling station. Travis’ brother Matthew said he paid $42.50 for 17 gallons of gasoline
at Mitchell’s Fill-up Station. Travis’ girlfriend Hailee paid $42.00 for 15 gallons at The
Guzzler Fill-up Station. Where would you suggest Travis go for the best deal?
1. What are the two quantities being compared?
Dollars and gallons
2. What are the rates for Matthew’s purchase and Hailee’s purchase?
Matthew: $42.50 for 17 gallons and Hailee: $42.00 for 15 gallons.
3. How much did Matthew pay for each gallon? How much did Hailee pay per gallon? Justify your
response. Write the two unit rates.
Divide the dollar amount by the number of gallons or write a proportion such as:
$42.50
$2.50

or $2.50 per gallon
Matthew:
17 gallons 1 gallon
$42.00
$2.80
Hailee:

$2.80 per gallon
15 gallons 1 gallon
4. Who got the better deal—Matthew or Hailee? Why?
Matthew. He paid $2.50 per gallon while Hailee paid $2.80 per gallon. Matthew paid 30 cents
less per gallon than Hailee  $2.80 – $2.50 = $0.30
5. How much does seven gallons of gas cost at The Guzzler Fill-up Station? Explain your
solution.
$2.80 x 7 gallons = $19.60. I multiplied the cost per gallons by the number of gallons.
6. How much gasoline could Travis get at Mitchell’s Fill-up Station if he had $25.00? Round
answers to the nearest tenth. Explain your solution.
10 gallons. I divided the amount Travis has ($25) by the unit rate ($2.50).
©2010, TESCCC
08/01/10
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 2 of 4) KEY
7. Complete the table and graph below:
Mitchell’s Fill-Up Station
# of Gallons
Process
Cost
1
2.50
2.51
2.517
2.5gal
17
Gallons
42.50
Students may use any numbers they choose in the table. The process is always
gallons x $2.50 = cost.
$42.50
$40.00
$37.50
$35.00
$32.50
$30.00
$27.50
$25.00
Cost
$22.50
$20.00
$17.50
$15.00
$12.50
$10.00
$7.50
$5.00
$2.50
2
4
6
8
10
12
Number of Gallons
©2010, TESCCC
08/01/10
14
16
18
20
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 3 of 4) KEY
8. Complete the table and graph below:
The Guzzler Fill-Up Station
# of Gallons
Process
Cost
1
2.80
12.80
Cost
15
42.00
152.80
Gallons
cost
Gal  2.80
The process is always gallons x $2.50 = cost. For simplicity, students may want to use the same
numbers in this table as in Mitchell’s Fill-Up Station.
$42.00
$35.00
$28.00
$21.00
$14.00
$7.00
0
3
6
9
12
Number of Gallons
©2010, TESCCC
08/01/10
15
18
8th Grade
Mathematics
Unit: 04 Lesson: 01
Gasoline Prices (pp. 4 of 4) KEY
Use the table and graph for The Guzzler Fill-Up Station to help check the reasonableness of
your answers to the following questions.
9. What does the point (3, 8.40) represent?
Three gallons costs $8.40.
10. What does the point (10, 28) represent?
Ten gallons costs $28.00.
11. What is the ordered pair that represents the unit rate?
(1, 2.80)
12. If Hailee spent $33.60, how many gallons of gas did she purchase?
12 gallons (33.60 divided by $2.80 per gallon)
13. If Hailee bought 8 gallons of gas, how much did she spend?
$22.40 (8 gallons times $2.80 per gallon)
In questions 14 – 15, you will compare the data in the tables for Mitchell’s Fill-Up Station
with the data for The Guzzler Fill-Up Station.
14. What is the same about the data in the tables?
Answers may vary. Sample answers:
1) Cost rises at a constant rate.
2) The process column is unit rate times # of gallons.
3) If the number of gallons rises by 1, the cost rises by the unit rate.
15. What is different about the data in the tables?
Answers may vary. Sample answers:
1) The Guzzler costs more per gallon, so the cost rises quicker.
2) Price per gallon is different
In questions 16 – 17, you will compare the data in the graphs for Mitchell’s Fill-Up Station
with the data for The Guzzler Fill-Up Station.
16. What is the same about the data in the graphs?
Answers may vary. Sample answers:
1) Both graphs make a line (are linear).
2) Both graphs include (0,0).
3) Both graphs rise from left to right.
17. What is different about the data in the graphs?
Answers may vary. Sample answers:
1) The only point they have in common is (0,0).
2) The line for The Guzzler Fill-Up Station rises faster than the line for Mitchell’s Fill-Up
Station.
©2010, TESCCC
08/01/10