1. Converting Customary Units
9-3
Converting Customary Units
Course 1
Warm Up
Problem of the Day
Lesson Presentation

2. Converting Customary Units
Course 1
9-3
Converting Customary Units
Warm Up
List the first five multiples of the following numbers.
3, 6, 9, 12, 15
12, 24, 36, 48, 60
36, 72, 108, 144, 180
48, 96, 144, 192, 240

3. Converting Customary Units
Course 1
9-3
Converting Customary Units
Problem of the Day
How much will it cost to build a fence that is 24 ft long, if it costs $20 to build a fence that is 15 ft long?
$32

4. Converting Customary Units
Course 1
9-3
Converting Customary Units
Learn to convert customary units of measure.

5. Converting Customary Units
Course 1
9-3
Converting Customary Units
You can use the information in the table below to convert one customary unit to another.
When you convert units of measure to another, you can multiply or divide by a conversion factor.

6. Additional Example 1A: Using a Conversion Factor
Course 1
9-3
Converting Customary Units
Additional Example 1A: Using a Conversion Factor
Convert 9 yards to feet.
Set up a conversion factor.
Think: yards to feet- 3 feet = 1 yd, so use
3 ft 1 yd
3 ft 1 yd
Multiply using the conversion factor. Cancel the common unit, yd.
9 yd x
9 yd = 27 ft
Write the unit you are converting to in the numerator and the unit you are converting from in the denominator.
Caution!

7. Additional Example 1B: Using a Conversion Factor
Course 1
9-3
Converting Customary Units
Additional Example 1B: Using a Conversion Factor
Convert 10,000 pounds to tons.
Set up a conversion factor.
Think: pounds to tons- 1 ton = 2,000 lbs, so
use
1 ton s 2,000 lbs
Multiply 10,000 lbs by the conversion factor. Cancel the common unit, lbs.
1 ton 2,000 lbs
10,000 lbs x
10,000 lbs = 5 tons

8. Converting Customary Units
Course 1
9-3
Converting Customary Units
Check It Out: Example 1A
Convert 3 quarts to pints.
Set up a conversion factor.
Think: quarts to pints- 2 pints = 1 quart, so use .
2 pt 1 qt
2 pt 1 qt
Multiply using the conversion factor. Cancel the common unit, qt.
3 qt x
3 quarts = 6 pints

9. Converting Customary Units
Course 1
9-3
Converting Customary Units
Check It Out: Example 1B
Convert 15,840 feet to miles.
Set up a conversion factor.
Think: feet to miles- 1 mile = 5,280 feet, so
use
1 mile 5,280 ft
Multiply 15,840 ft by the conversion factor. Cancel the common unit, ft.
1 mi s 5,280 ft
15,840 ft x
15,840 feet = 3 miles

10. Converting Customary Units
Course 1
9-3
Converting Customary Units
Another way to convert units is to use proportions.
A proportion shows that two ratios are equivalent. Use a conversion factor for one of the ratios.
Remember!

11. Additional Example 2: Converting Units of Measure by Using Proportions
Course 1
9-3
Converting Customary Units
Additional Example 2: Converting Units of Measure by Using Proportions
Convert 3 quarts to cups.
Convert quarts to cups.
3 qt = cups
1 quart is 4 cups. Write a proportion. Use a variable for the value you are trying to find.
1 qt 4 c
3 qt x =
1 • x = 4 • 3
The cross products are equal.
1x = 12
Divide both sides by 1 to undo the multiplication.
x = 12
3 quarts = 12 cups.

12. Converting Customary Units
Course 1
9-3
Converting Customary Units
Check It Out: Example 2
Convert 144 cups to gallons.
Convert cups to gallons.
144 cups = gallons.
1 gallon is 16 cups. Write a proportion. Use a variable for the value you are trying to find.
1 gal 16 c
x c =
16 • x = 1 • 144
The cross products are equal.
16x = 144
Divide both sides by 16 to undo multiplication.
x = 9
144 cups = 9 gallons.

13. Understand the Problem
Course 1
9-3
Converting Customary Units
Additional Example 3: Problem Solving Application
The football goal posts are 30 feet tall. How many inches is this? 1
Understand the Problem
The answer will be the height of the goal posts in inches.
List the important information:
• The height of the goal posts are 30 feet tall.

14. Additional Example 3 Continued
Course 1
9-3
Converting Customary Units
Additional Example 3 Continued 2
Make a Plan
Make a table from the information to show the number of inches in 1, 2, and 3 feet. Then find the number of inches in n feet.

15. Additional Example 3 Continued
Course 1
9-3
Converting Customary Units
Additional Example 3 Continued
Solve 3
Feet
Inches 1 12 2 24 3 36 n
12n
Look for a Pattern.
1 • 12 = 12
2 • 12 = 24
3 • 12 = 36
n • 12 = 12n
30 • 12 = 360 so, the goal posts are 360 inches tall.

16. Additional Example 3 Continued
Course 1
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Converting Customary Units
Additional Example 3 Continued 4
Look Back
Round 12 to 10. Then multiply by 30.
30 • 10 = 300
The answer is reasonable because 360 is close to 300.

17. Understand the Problem
Course 1
9-3
Converting Customary Units
Check It Out: Example 3
The soccer field is 110 yards long. How many inches is this? 1
Understand the Problem
The answer will be the length of the soccer field in inches.
List the important information:
• The soccer field is 110 yards long.

18. Check It Out: Example 3 Continued
Course 1
9-3
Converting Customary Units
Check It Out: Example 3 Continued 2
Make a Plan
Make a table from the information to show the number of inches in 1, 2, and 3 yard. Then find the number of inches in n yards.

19. Check It Out: Example 3 Continued
Course 1
9-3
Converting Customary Units
Check It Out: Example 3 Continued
Solve 3
Yard
Inches 1 36 2 72 3
108 n
36n
Look for a Pattern.
1 • 36 = 36
2 • 36 = 72
3 • 36 = 108
n • 36 = 36n
110 • 36 = 3,960 so, the soccer field is 3,960 inches long.

20. Check It Out: Example 3 Continued
Course 1
9-3
Converting Customary Units
Check It Out: Example 3 Continued 4
Look Back
Round 110 to 100. Then multiply by 36.
36 • 100 = 3,600
The answer is reasonable because 3,960 is close to 3,600.

21. Converting Customary Units Insert Lesson Title Here
Course 1
9-3
Converting Customary Units
Insert Lesson Title Here
Lesson Quiz
1. Convert 5 yards to inches.
2. Convert 16 tons to pounds.
3. Convert 11 quarts to cups.
4. A project requires 288 inches of tape. How many yards is this?
180 inches
32,000 pounds
44 cups
8 yards