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

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

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

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

Course 1 8-3 Proportions and Customary Measurement

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.

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.

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.

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.

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.

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.

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 2 lb. 4. 7,920 ft 1.5 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