Ratios, Rates, Unit Rates, & Equivalent Ratios
Suzy eats 15 cookies in 5 minutes. What is the ratio of cookies to minutes?
15/5 ÷ 5 = 3/1 3 cookies: 1 minute
Ms. Nelson made ribbons for her volleyball team. If she made 244 in 61 minutes, how many ribbons did she make each minute?
244/61 ÷ 61 = 4/1 4 ribbons per minute
Mr. Wolski has 36 microscopes for every 12 beakers. What is the ratio of microscopes to beakers?
36/ 12 ÷ 12 = 3/1 . 3 microscopes: 1 beaker
An animal shelter has 45 kittens and 9 puppies available for adoption. What is the ratio of kittens to puppies?
45/9 ÷ 9 = 5/1 . 5 kittens: 1 puppy
Mrs. Lolos baked 54 cupcakes in 9 minutes. How many cupcakes did she bake per minute?
54/9 ÷ 9 = 6/1 6 cupcakes per minute
Joe read 60 pages in 10 minutes. How many pages did he read per minute?
60/10 ÷ 10 = 6/1 6 pages per one minute
If a truck travels 66 miles in 30 minutes, what is the rate at which the car is traveling per minute?
66/30÷30 = Answer = 2.2
A class has 7 boys and 21 girls. What is the ratio of boys to girls?
7/21 ÷ 7 = 1/3 . 1 boy: 3 girls
Mrs. Tuller has 9 dogs to every 27 pets she has. What is the ratio of dogs to pets?
9/27 ÷ 9 = 1/3 1 dog: 3 pets
Are these ratios equivalent? Mr. Jones has 20 girls out of 30 students in his math club. The art club has 50 girls out of 60 students. Are the ratios equivalent?
No! 20/30 ÷ 10 = 2/3 50/60 ÷ 10 = 5/6 2/3 ≠ 5/6
Are these ratios equivalent? $24 for 8 books; $36 for 13 books
YES! They are equivalent because $24 ÷ 8 = 3 and $36 ÷ 13 = 3
rate
a ratio comparing two quantities of different kinds of units
ratio
comparison of two numbers by division
Joe is traveling a half marathon. In practice, he runs 4 miles in 21 minutes. If he continues at the same rate, how many miles will he run in 189 minutes?
miles 4 12 ? minutes 21 63 189 Answer = 36
equivalent ratio
multiply or divide two related quantities by the same number 2:6=10:30
Lily purchased 160 pencils for $24. If she needs to buy 20 more pencils, how much will she pay if she is charged the same rate?
pencils . 160 80 20 cost in dollars . 24 12 ? Answer = 3
unit rate
when a rate is simplified so that it has a denominator of 1
