Unit Rates and Proportions

Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities where one of the quantities is expressed as a quantity of one. For example, if a car travels 300 miles in 5 hours, the unit rate is 60 miles per hour.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How do you find a unit rate from a ratio?

Back

To find a unit rate from a ratio, divide the first quantity by the second quantity to express it as a quantity of one. For example, if the ratio is 10 apples for $5, the unit rate is $5/10 apples = $0.50 per apple.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if 1/2 = 2/4, then these two ratios are in proportion.

Tags

CCSS.7.RP.A.2B

Front

How can you solve for a missing value in a proportion?

Back

To solve for a missing value in a proportion, cross-multiply the ratios and then solve the resulting equation. For example, if a/b = c/d, then ad = bc.

Tags

CCSS.7.RP.A.3

Front

If 3 pizzas feed 9 people, how many pizzas are needed for 36 people?

Back

12 pizzas are needed. (3 pizzas / 9 people) = (x pizzas / 36 people) leads to x = 12.

Tags

CCSS.6.RP.A.3B

Front

What is the formula to calculate unit price?

Back

Unit price = Total price / Number of units. For example, if 5 ice cream bars cost $12.25, the unit price is $12.25 / 5 = $2.45 per ice cream bar.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

If a recipe requires 2 cups of flour for 4 servings, how much flour is needed for 10 servings?

Back

5 cups of flour are needed. (2 cups / 4 servings) = (x cups / 10 servings) leads to x = 5.

Tags

CCSS.6.RP.A.3B

Front

What is the relationship between unit rates and proportions?

Back

Unit rates can be used to create proportions. If you know the unit rate, you can set up a proportion to find unknown quantities.

Tags

CCSS.7.RP.A.3

Front

How do you convert a ratio to a percentage?

Back

To convert a ratio to a percentage, divide the first number by the second number and then multiply by 100. For example, the ratio 1:4 is (1/4) * 100 = 25%.

Front

If 150 people wait 20 minutes for a ride, how long will 1200 people wait?

Back

160 minutes. The waiting time increases proportionally with the number of people.

Tags

CCSS.7.RP.A.3