Ratios and Scales

What is a Ratio?

• Is a comparison of two quantities 
• To multiply two fractions 
• A number over another number
• Two decimals that can be multiplied

What is the ratio of red apples to green apples

• 7 apples to 3 green
• 4 red apples to 7 apples
• 4 red apples to 3 green apples
• 3 green apples to 4 red apples

There are 4 birds and 6 snakes. What is the ratio of birds to total animals?

• 4/10
• 4/6
• 6/4
• 10/4

A class has 15 boys and 20 girls. What is the boy:girl ratio in simplest form?

• 4 to 5
• 10 to 13
• 3:4
• 3:5

The unitary method involves...

• Find the total number of parts in a ratio

• Find the value of the number of parts required in the ratio

• Find the total number of ratios in the part

• Find the value of one part

To make coffee, one small scoop of coffee grounds is added to 2 cups of water. Use the ratio table to find how many cups of water to use for 5 scoops of coffee.

• 4 cups of water

• 6 cups of water

• 10 cups of water

• 8 cups of water

Which of the following ratios are not equivalent to 1/2

• 2/4

• 3/6

• 6/10

• 30/60

• x = 40

• x = 2500

• x = 250

• x = 2.5

In a certain apartment building, the ratio of tenants to cars is 3:5. If there are 30 tenants, how many cars are there?

• 35
• 60
• 18
• 50

• 3:4

• 8:6

• 28:21

• 4:3