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Warm-up: On page. Write each ratio in simplest form. 48 : 12 36 to 9 75 to 15 42 : 7 125 to 5. Rates. What is rate?. a ratio that compares two quantities measured in different units. You have 2 buckets of ice cream for 11 people 2 buckets of ice cream / 11 people. Example 1.
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Warm-up: On page. Write each ratio in simplest form. • 48 : 12 • 36 to 9 • 75 to 15 • 42 : 7 • 125 to 5
What is rate? • a ratio that compares two quantities measured in different units. • You have 2 buckets of ice cream for 11 people 2 buckets of ice cream/11 people
Example 1 You drive 180 mi in 3 hrs 180 mi/3 hrs or 60 mi/hr
What is a unit rate? HAS A DENOMINATOR OF 1! Divide numerator by denominator! Or you can reverse. The numerator can be one instead. It depends on how you set up your ratio.
Example 2: My heart beats 150 times in 2 minutes. Rate: 150 heartbeats 2 minutes Unit Rate (Divide to get it): 150 ÷ 2 = 75 heartbeats per minute. 75 heartbeats = 1 minute
Example 3: Find the Unit Rate Amy can read 88 pages in 4 hours. What is the unit rate? (How many pages can she read per hour?) 88 pages 22 pages / hour 4 hours 22 pages = 1 hour
Example 4: Find the Unit Rate A box of crackers has 420 calories in 6 servings. Find the unit rate for 1 serving of crackers. 420 calories 70 calories / serving 6 servings 70 calories = 1 serving
How do you compare unit prices? • Use division to find the unit prices (rate) of both products. • Smaller number (costs less) is the better value.
Example 5 Juice is sold in two different sizes. A 48-fluid ounce bottle costs $2.07. A 32-fluid ounce bottle costs $1.64. Which is the better buy? $2.07 $0.04 per fl.oz. 0.043125 48 fl.oz. $1.64 $0.05 per fl.oz. 0.05125 32 fl.oz. The 48 fl.oz. bottle is the better value because it is $0.01 less per fluid ounce.
Example 6 You can buy 3 bagels for $2.85 or 5 bagels for $4.00. Which is the better buy? $2.85 $0.95 / 1 bagel 3 bagels $4.00 $0.80 / 1 bagel 5 bagels The 5 bagels are the better value because it costs $0.15 less per bagel.