9-3

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

2. 9-3 Converting Customary Units Course 1 Warm Up List the first five multiples of the following numbers. 1.3 2. 12 3. 36 4. 48 3, 6, 9, 12, 15 12, 24, 36, 48, 60 36, 72, 108, 144, 180 48, 96, 144, 192, 240

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

5. 9-3 Converting Customary Units Course 1 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. 9-3 Converting Customary Units Caution! Write the unit you are converting to in the numerator and the unit you are converting from in the denominator. 3 ft 1 yd Think: yards to feet- 3 feet = 1 yd, so use . Course 1 Additional Example 1A: Using a Conversion Factor Convert 9 yards to feet. Set up a conversion factor. 3 ft 1 yd Multiply using the conversion factor. Cancel the common unit, yd. 9 yd x 9 yd = 27 ft

7. 9-3 Converting Customary Units Think: pounds to tons- 1 ton = 2,000 lbs, so use . 1 ton s2,000 lbs Course 1 Additional Example 1B: Using a Conversion Factor Convert 10,000 pounds to tons. Set up a conversion factor. 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. 9-3 Converting Customary Units Think: quarts to pints- 2 pints = 1 quart, so use . 2 pt 1 qt Course 1 Check It Out: Example 1A Convert 3 quarts to pints. Set up a conversion factor. 2 pt 1 qt Multiply using the conversion factor. Cancel the common unit, qt. 3 qt x 3 quarts = 6 pints

9. 9-3 Converting Customary Units Think: feet to miles- 1 mile = 5,280 feet, so use . 1 mile 5,280 ft Course 1 Check It Out: Example 1B Convert 15,840 feet to miles. Set up a conversion factor. Multiply 15,840 ft by the conversion factor. Cancel the common unit, ft. 1 mi s5,280 ft 15,840 ft x 15,840 feet = 3 miles

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

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

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

13. 9-3 Converting Customary Units 1 Understand the Problem Course 1 Additional Example 3: Problem Solving Application The football goal posts are 30 feet tall. How many inches is this? 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. 9-3 Converting Customary Units Make a Plan 2 Course 1 Additional Example 3 Continued 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. 9-3 Converting Customary Units 3 Solve Course 1 Additional Example 3 Continued 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. 9-3 Converting Customary Units Look Back 4 Course 1 Additional Example 3 Continued Round 12 to 10. Then multiply by 30. 30 • 10 = 300 The answer is reasonable because 360 is close to 300.

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

18. 9-3 Converting Customary Units Make a Plan 2 Course 1 Check It Out: Example 3 Continued 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. 9-3 Converting Customary Units 3 Solve Course 1 Check It Out: Example 3 Continued 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. 9-3 Converting Customary Units Look Back 4 Course 1 Check It Out: Example 3 Continued 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. 9-3 Converting Customary Units Course 1 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