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Example 1-4b Objective Express ratios as fractions in simplest form and determine unit rates

Example 1-4b Vocabulary Ratio A comparison of two numbers by division

Example 1-4b Vocabulary Rate A comparison of two quantities with different types of units

Example 1-4b Vocabulary Unit Rate When a rate is simplified so it has a denominator of 1

Example 1-4b Vocabulary Math Symbols Approximately equal to 

Lesson 1 Contents Example 1Write Ratios in Simplest Form Example 2Write Ratios in Simplest Form Example 3Find a Unit Rate Example 4Compare Unit Rates

Example 1-1a Express 12 blue marbles out of 18 marbles in simplest form. Answer: The ratio = Write rate as fraction Put fraction in calculator and simplify 1/4 Begin with numerator Put fraction bar Write denominator

Example 1-1b Express 5 blue marbles out of 20 marbles in simplest form. Answer: Ratio = 1/4

Example 1-2a Express 10 inches to 2 feet in simplest form. Write rate as fraction Cancel like units 2/4 Must have same unit in numerator as in denominator Convert 2 feet to 24 inches. Convert to the smaller unit which is inches

Example 1-2a Express 10 inches to 2 feet in simplest form. Answer: The ratio = 2/4 Put fraction in calculator and simplify

Example 1-2b Express 14 inches to 2 feet in simplest form. Answer: 2/4

Example 1-3a READING Yi-Mei reads 141 pages in 3 hours. How many pages does she read per hour? Answer: Yi-Mei reads an average of 47 pages per hour 3/4 Write rate as fraction Find a unit rate Divide the numerator by the denominator 141 pages ÷ 3 47 pages Divide the denominator by the denominator 3 hours ÷ 3 1 hour

Example 1-3b 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: miles per hour 3/4

Example 1-4a 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: Jellybeans: 4/4 Write a rate for each item Find unit rates of each item

Example 1-4a 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: Divide numerator by denominator 4/4 ÷ 2 $6.25 Divide denominator by denominator ÷ 2 1 pound

Example 1-4a 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? Divide numerator by denominator 4/4 $4.77 Divide denominator by denominator 1 pound Jellybeans: ÷ 5

Example 1-4a Answer: Jellybeans cost $1.48 per pound less than almonds Almonds: Jellybeans: (Almonds) $6.25 – $4.77 (Jellybeans) Which item costs less per pound? By how much? 4/4 Since the denominators are both the same (1 pound) then compare the numerators Jellybeans cost less Since the denominators are both the same (1 pound) then subtract numerators $1.48

Example 1-4b 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

End of Lesson 1 Assignment Lesson 4:1Ratios & Rates All