lesson menu main idea and new vocabulary example 1:equivalent ratios of larger quantities example...

Main Idea and New Vocabulary

Example 1:Equivalent Ratios of Larger Quantities

Example 2:Equivalent Ratios of SmallerQuantities

Example 3:Use Scaling

Example 4:Real-World Example: Use a RatioTable

• Use ratio tables to represent and solve problems involving equivalent ratios.

• ratio table

• equivalent ratio• scaling

Equivalent Ratios of Larger Quantities

BEANS A recipe calls for 5 cups of water for each cup of black beans. How many cups of water should be used for 4 cups of black beans.

Use a ratio table. Since 1 × 4 = 4, multiply each quantity by 4.

Answer: So, use 20 cups of water for 4 cups of beans.

RICE A recipe calls for 2 cups of water for each cup of rice. How many cups of water should be used for 3 cups of rice?

A. 5 cups of water

B. 6 cups of water

C. 8 cups of water

D. 9 cups of water

FLOWERS The state flower of Florida is the orange blossom. Find how many petals an orange blossom has.

Equivalent Ratios of Smaller Quantities

Method 1 Find a pattern and extend it.

For every one flower, subtract 5 petals.

Equivalent Ratios of Smaller Quantities

Equivalent Ratios of Smaller Quantities

Method 2 Divide each quantity by the samenumber.

Answer: So, one orange blossom has 5 petals.

In an orange peeling contest, Steven peeled 18 oranges in 60 seconds. If he peeled the oranges at a constant rate, determine about how many oranges he peeled in 10 seconds.

A. 3 oranges

B. 6 oranges

C. 10 oranges

D. 18 oranges

Use Scaling

CLOTHING Coco used 12 yards of fabric to make 9 blouses. Find the number of blouses she could make with 20 yards of fabric.

There is no whole number by which you can multiply 12 to get 20. So, scale back to 4 and then scale forward to 20.

Use Scaling

Answer: So, Coco could make 15 blouses with 20 yards of fabric.

WEIGHT A child’s weight is 55 pounds. Estimate his weight in kilograms.

?A. 25 kilograms

B. 33 kilograms

C. 43 kilograms

D. 55 kilograms

PACKAGING It takes a worker 70 minutes to pack 120 cartons of books. The worker has 14 minutes of work left. Use a ratio table to find how many cartons of books the worker can pack in 14 minutes.

Use a Ratio Table

Set up a ratio table.

?

Use scaling to find the desired quantity.

Use a Ratio Table

Answer: In 14 minutes, the worker can pack 24 cartons of books.

AUTOMOBILES The Wilson’s van can travel 350 miles on a 15-gallon tank of gas. Use a ratio table to determine how many gallons they will need for a 420-mile trip.

A. 12.5 gallons

B. 18 gallons

C. 23 gallons

D. 28 gallons