1. Proportions and Customary Measurement
8-3
Proportions and Customary Measurement
Course 1
Warm Up
Problem of the Day
Lesson Presentation

2. 8-3 Proportions and Customary Measurement Warm Up
Course 1
8-3
Proportions and Customary Measurement
Warm Up
Find the missing value in each proportion.
1. =
2. =
3. =
4. = 4 1 __ 24 x __
x = 6 x 30 __ 5 6 __
x = 25 14 16 __ x 40 __
x = 35 8 x __ 12 18 __
x = 12

3. 8-3 Proportions and Customary Measurement Problem of the Day
Course 1
8-3
Proportions and Customary Measurement
Problem of the Day
There are 4 ounces in a gill. There are 4 gills in a pint. There are 8 pints in a gallon. How many ounces are the same as the total of 3 gallons, 3 pints, 3 gills, and 3 ounces?
447

4. Course 1
8-3
Proportions and Customary Measurement
Learn to use proportions to make conversions within the customary system.

5. Course 1
8-3
Proportions and Customary Measurement

6. Additional Example 1A: Using Proportions to Convert Measurements
Course 1
8-3
Proportions and Customary Measurement
Additional Example 1A: Using Proportions to Convert Measurements
A. Sonja went hiking for 4 hours. For how many minutes did she go hiking?
1 hour is 60 minutes. Write a proportion. Use a variable for the value you are trying to find.
1 hr
60 min
_____
4 hr
x min
____ =
60 • 4 = 1 • x
The cross products are equal.
240 = x
Sonja hiked for 240 minutes.

7. Additional Example 1B: Using Proportions to Convert Measurements
Course 1
8-3
Proportions and Customary Measurement
Additional Example 1B: Using Proportions to Convert Measurements
B. Mr. Lee is 72 inches tall. Find his height in feet.
1 foot is 12 inches. Write a proportion. Use a variable for the value you are trying to find.
1 ft
12 in
____
x ft
72 in.
____ =
12 • x = 1 • 72
The cross products are equal.
12x = 72
x is multiplied by 12.
12x 12
___ 72 12
___
Divide both sides by 12 to undo the multiplication. =
x = 6
Mr. Lee is 6 feet tall.

8. Additional Example 1C: Using Proportions to Convert Measurements
Course 1
8-3
Proportions and Customary Measurement
Additional Example 1C: Using Proportions to Convert Measurements
C. Hunter used 56 cups of water to wash his car. How many gallons of water did he use?
1 gallon is 16 cups. Write a proportion. Use a variable for the value you are trying to find.
1 gal
16 cups
_______
x gal
56 cups
______ =
16 • x = 1 • 56
The cross products are equal.
16x = 56
x is multiplied by 16.
16x 16
___ 56 16
___
Divide both sides by 16 to undo the multiplication. =
x = 3.5
Hunter used 3.5 gallons of water to wash his car.

9. 8-3 Proportions and Customary Measurement Try This: Example 1A
Course 1
8-3
Proportions and Customary Measurement
Try This: Example 1A
A. Helga went biking for 3 hours. For how many minutes did she go biking?
1 hour is 60 minutes. Write a proportion. Use a variable for the value you are trying to find.
1 hr
60 min
_____
3 hr
x min
____ =
60 • 3 = 1 • x
The cross products are equal.
180 = x
Helga biked for 180 minutes.

10. 8-3 Proportions and Customary Measurement Try This: Example 1B
Course 1
8-3
Proportions and Customary Measurement
Try This: Example 1B
B. Ms. Hagan is 60 inches tall. Find her height in feet.
1 foot is 12 inches. Write a proportion. Use a variable for the value you are trying to find.
1 ft
12 in.
____
x ft
60 in.
____ =
12 • x = 1 • 60
The cross products are equal.
12x = 60
x is multiplied by 12.
12x 12
___ 60 12
___
Divide both sides by 12 to undo the multiplication. =
x = 5
Ms. Hagan is 5 feet tall.

11. 8-3 Proportions and Customary Measurement Try This: Example 1C
Course 1
8-3
Proportions and Customary Measurement
Try This: Example 1C
C. Seymour used 40 cups of water to wash his dog. How many gallons of water did he use?
1 gallon is 16 cups. Write a proportion. Use a variable for the value you are trying to find.
1 gal
16 cups
_______
x gal
40 cups
______ =
16 • x = 1 • 40
The cross products are equal.
16x = 40
x is multiplied by 16.
16x 16
___ 40 16
___
Divide both sides by 16 to undo the multiplication. =
x = 2.5
Seymour used 2.5 gallons of water to wash his dog.

12. Insert Lesson Title Here
Course 1
8-3
Proportions and Customary Measurement
Insert Lesson Title Here
Lesson Quiz
Find the missing value.
1. in. = 6 yd
2. 24 pt = gal
Compare. Write <, >, or =.
3. 42 oz lb.
4. 7,920 ft mi
5. If your family is going to take a 3-week vacation, how many days will you be gone?
216 3 1 2 __
> =
21 days