Unit Rates & 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 you travel 150 miles in 5 gallons of gas, the unit rate is 30 miles per gallon.

Front

How do you calculate a unit rate?

Back

To calculate a unit rate, divide the first quantity by the second quantity. For example, if you have 150 miles and 5 gallons, you divide 150 by 5 to get 30 miles per gallon.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if a/b = c/d, then a, b, c, and d are in proportion.

Front

How do you solve a proportion?

Back

To solve a proportion, you can cross-multiply and then divide. For example, if you have 2/3 = x/12, you cross-multiply to get 2*12 = 3*x, then solve for x.

Front

What does it mean to simplify a ratio?

Back

Simplifying a ratio means reducing it to its simplest form by dividing both terms by their greatest common factor. For example, the ratio 4:8 simplifies to 1:2.

Front

If there are 5 dogs for every 20 cats, what is the simplified ratio of dogs to cats?

Back

The simplified ratio of dogs to cats is 1:4.

Front

What is the relationship between unit rates and proportions?

Back

Unit rates can be used to set up proportions. For example, if you know the unit rate of a car's fuel efficiency, you can use it to find out how much fuel is needed for a longer trip.

Front

How do you find the total cost when given a unit price?

Back

To find the total cost, multiply the unit price by the number of units. For example, if one pair of socks costs $4 and you buy 3 pairs, the total cost is 4 * 3 = $12.

Front

What is the formula for finding a unit rate?

Back

The formula for finding a unit rate is: Unit Rate = Total Quantity / Number of Units.

Front

If Eric bought 4 pairs of socks for $9, what is the unit price per pair?

Back

The unit price per pair is $9 / 4 = $2.25.