Lesson 4.2

• Math
• 6th Grade

Lesson 4.2 Ratios and Rates

Learning Objective 

We will be able to determine the ratio and rate of a problem. 

Why? 

• Junior high and high school.
• Daily life- driving, shopping, 

What is a ratio in your own words?

Rate

Rate: a ratio that compares 2 quantities of different units (labels). 

• miles per hour (mph)miles per gallon (mpg)
• beats per minute (bpm)

What is a rate in your own words?

Complete the table

# of boxes	1
Cookies	6

2

5

4

18

12

3

24

30

Unit Rate

Unit Rate: a rate that compares something to 1 unit. 

• Buy 2 for $4                                     Buy 1 for $2

Unit Rate- Your turn 

Unit Rate: a rate that compares something to 1 unit. 

• Buy 3 for $18                                    Unit Rate? 

Unit Rate?  

• 48 minutes                           

12 miles   

Unit Rate?  

• 48 minutes ÷ 12                          

12 miles   ÷ 12

Unit Rate?  

• 48 minutes ÷ 12                          4 min 

12 miles   ÷ 12

1 mile

Unit Rate?  

• 48 minutes ÷ 12                          4 min 

12 miles   ÷ 12

1 mile

4 minutes per mile 

Unit Rate?  

Joaquin entered a hot dog eating contest. He ate 72 hot dogs in 36 minutes. What is the unit rate for hot dogs in 1 minute?  

Unit Rate?   

• 72 hot dogs                              

36 minutes

Unit Rate?   

• 72 hot dogs    ÷ 36                      

36 minutes÷ 36

Unit Rate?

• 72 hot dogs    ÷ 36                      2 hot dogs 

36 minutes÷ 36

  1 minute

2 hot dogs per minute 

Unit Rate?  

Daisy went on a jog and traveled 30 miles in 6 hours. What is the unit rate for miles in 1 hour? 

Unit Rate- Your Turn 

• 30 miles ÷ 6                      5 miles 

6 hours÷ 6

  1 hour

5 miles per hour 

Three ways to write a ratio?
There are 5 cats to every 3 dogs.

Claire saves $20 each week to buy a tabby cat. Complete the table to find out how much money Claire will have on the fifth week.  

Cat $		40
Week	1	2		4	5

20

60

100

80

3

What is the ratio?

1. 2:5
2. 5:2
3. 5 to 2
4. 2:7

Explain how "six muffins per box"
is a ratio?

What is the ratio of the length to width?

1. 8:2
2. 1 to 4
3. 2/8
4. 16:2

Ava has 2 orange cats and 3 gray cats. Compare the ratio of orange cats to the total number of cats.

1. 2 to 5
2. 2:3
3. 3:2
4. 5/3