Objective:Objective:Objective:Objective:

Students will express ratios and Students will express ratios and rates as fractions (8-1).rates as fractions (8-1).

Vocabulary:• Rate- a ratio of two measurements

that have different units.• Ratio- comparison of two numbers

by division

Ratio as a fraction:• Read all directions!!!!!• Write the problem down.• Write the ratio as a fraction. The

first # = the numerator. The second # = the denominator.

• Last, simplify.

Ratio as a rate:• Read all directions!!!!!• Write down the problem.• Write problem as a fraction (fraction

may be a improper fraction).• Divide denominator into numerator

in order to simplify.• Be careful when working with money.

Notes:• A ratio can be written 4 ways: 24 to 108 24 out of 108 24:108 24 over 108 (fraction)

Examples• Express the ratio that compares the

number of strawberries to the total number of pieces of fruit as a fraction in simplest form.

Strawberries 4

Examples• Express the ratio that compares the

number of strawberries to the total number of pieces of fruit as a fraction in simplest form.

Strawberries 4Pieces of fruit 10

Examples• Express the ratio that compares the

number of strawberries to the total number of pieces of fruit as a fraction in simplest form.

Strawberries 4 = 2 Pieces of fruit 10 = 5

Examples• Express the ratio that compares the number

of strawberries to the total number of pieces of fruit as a fraction in simplest form.

Strawberries 4 = 2 The GCF of 4 and Pieces of fruit 10 = 5 10 is 2. Divide the numerator and the denominator by the GCF 2. The ratio in simplest form is 2 5

• Express the ratio 7 inches of rain in 28 days as a rate.

7 inches

• Express the ratio 7 inches of rain in 28 days as a rate.

7 inches 28 days

• Express the ratio 7 inches of rain in 28 days as a rate.

• 7 inches = 0.25 inch 28 days = 1 day

Divide the numerator and thedenominator by 28 to get a denominator

of 1.

The total rain fall is equivalent to 0.25 inch each day.

• Dhara purchased a 14.5 ounce bag of chips for $3.19. What was the cost per ounce?

Explore You know that the 14.5 ounce bag of chips costs $3.19 You need to find the cost per ounce.Plan Use a rate to compare the

cost to the weight.

Solve $3.19 = $0.22 14.5 oz. = 1 oz. Divide the numerator and the denominator by 14.5 to get a denominator of 1. 3.19 ÷ 14.5 = 0.22 The cost is 22 cents per ounce.

Examine $0.22 x 14.5 = $3.19 So the answer is correct.

Write each ratio in three different ways:

• 7 carnations out of 24 flowers

• 15 mint chip cookies in a bag of 34 cookies

Guided Practice

Write each ratio in three different ways:• 7 carnations out of 24 flowers

7 out of 24 7 to 24 7:24

• 15 mint chip cookies in a bag of 34 cookies

15 to 34 15 out of 34 15 34

Express each ratio as a fraction in simplest from:

• 16 beagles out of 24 dogs

• 10 emeralds out of 25 gems

Express each ratio as a fraction in simplest from:

• 16 beagles out of 24 dogs 16 beagles = 2 beagles 24 dogs = 3 dogs

• 10 emeralds out of 25 gems 10 emeralds = 2 emeralds 25 gems = 5 gems

Express each ratio as a rate:

• 120 words in 3 minutes

• 5 soft drinks for $3.25

• The fastest running bird is the ostrich. An ostrich can run 240 miles in 6 hours. What is the average speed of an ostrich?

Express each ratio as a rate:

• 120 words in 3 minutes 120 words = 40 words 3 minutes = 1 min.The answer is 40 words per minute.

• 5 soft drinks for $3.25 $3.25 = $0.65 5 soft drinks = 1 soft drink The answer is $0.65 per soft drink.

• The fastest running bird is the ostrich. An ostrich can run 240 miles in 6 hours. What is the average speed of an ostrich?

240 miles = 40 miles 6 hours = 1 hour

The answer is 40 miles per hour.