6-1 Ratios and Unit Rate

In September 2012, there were 8 core teachers and 200 students in 7th grade. Find the ratio of teachers to students. Write answer in lowest terms.

# of teachers

# of students=

ratio: a comparison of two numbers

Ratios can be written three different ways.

Example: Sarah was practicing free throws and made 3 shots out of 10.

3:10 3 to 10

three to ten

1.) Write the ratio of girls to boys in the classroom in three different ways.

2.) Write the ratio of boys to students in the classroom in three different ways.

Examples: Tell whether the ratio is in simplest form. If not write it in simplest form. Then write in two other ways.

1.) 20 : 60  2.) 4 to 5

3.) 20 dogs to 15 cats 4.) 32 PC's to 40 laptops

 Ex. 75 miles 3  = 25 miles 3 hours 3 1 hour

Unit rate - A rate in which the second quantity is one

Rate - A ratio that compares two different quantities measured in different units.

75 miles in 3 hours

Ex.

1.) A box of wheat crackers contains 420 calories and has a total of 6 servings. What is the unit rate per serving?

2.) If six peaches cost $3.84, what is the unit rate?

Find the unit rate.

3.)

Demonstrate Understanding: Express each ratio in lowest terms. Then write the ratio three ways.

1.) 28:70 2.) 400 boys to 450 girls

5.) You can buy 6 ounces of yogurt for $0.66, or 32 ounces for $3.20. Find each unit cost. Which is the better buy?

Find the unit rate.

3.) 4.)