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Click the mouse button or press the Space Bar to display the answers. Objective Express ratios as fractions in simplest form and determine unit rates Vocabulary Ratio A comparison of two numbers by division Vocabulary Rate A comparison of two quantities with different types of units Vocabulary Unit Rate When a rate is simplified so it has a denominator of 1 Vocabulary Math Symbols Approximately equal to Example 1 Write Ratios in Simplest Form Example 2 Write Ratios in Simplest Form Example 3 Find a Unit Rate Example 4 Compare Unit Rates Express 12 blue marbles out of 18 marbles in simplest form. Write rate as fraction Begin with numerator Put fraction bar Write denominator Put fraction in calculator and simplify Answer: The ratio = 1/4 Express 5 blue marbles out of 20 marbles in simplest form. Answer: Ratio = 1/4 Express 10 inches to 2 feet in simplest form. Write rate as fraction Must have same unit in numerator as in denominator Convert to the smaller unit which is inches Convert 2 feet to 24 inches. Cancel like units 2/4 Express 10 inches to 2 feet in simplest form. Put fraction in calculator and simplify Answer: The ratio = 2/4 Express 14 inches to 2 feet in simplest form. Answer: 2/4 READING Yi-Mei reads 141 pages in 3 hours. How many pages does she read per hour? Write rate as fraction Find a unit rate 141 pages ÷ 3 3 hours ÷ 3 47 pages 1 hour Divide the numerator by the denominator Divide the denominator by the denominator Answer: Yi-Mei reads an average of 47 pages per hour 3/4 TRAVEL On a trip from Columbus, Ohio, to Myrtle Beach, South Carolina, Lee drove 864 miles in 14 hours. What was Lee’s average speed in miles per hour? Answer: 61.71 miles per hour 3/4 SHOPPING Alex spends $12.50 for 2 pounds of almonds and $23.85 for 5 pounds of jellybeans. Which item costs less per pound? By how much? Almonds: Write a rate for each item Find unit rates of each item Jellybeans: 4/4 SHOPPING Alex spends $12.50 for 2 pounds of almonds and $23.85 for 5 pounds of jellybeans. Which item costs less per pound? By how much? ÷2 Almonds: ÷2 $6.25 1 pound Divide numerator by denominator Divide denominator by denominator 4/4 SHOPPING Alex spends $12.50 for 2 pounds of almonds and $23.85 for 5 pounds of jellybeans. Which item costs less per pound? By how much? ÷5 Jellybeans: ÷5 $4.77 1 pound Divide numerator by denominator Divide denominator by denominator 4/4 Which item costs less per pound? By how much? Almonds: Jellybeans: Jellybeans cost less Since the denominators are both the same (1 pound) then compare the numerators Since the denominators are both the same (1 pound) then subtract numerators (Almonds) $6.25 – $4.77 (Jellybeans) $1.48 Answer: Jellybeans cost $1.48 per pound less than almonds 4/4 * SHOPPING Cameron spends $22.50 for 2 pounds of macadamia nuts and $31.05 for 3 pounds of cashews. Which item costs less per pound? By how much? Answer: Cashews cost $0.90 less than macadamia nuts 4/4 Assignment Lesson 4:1 Ratios & Rates 10 - 30 All