Rates, Ratios and Unit Rates

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 one unit. For example, if you earn $90 in 5 hours, the unit rate is $18 per hour.

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 14 inches of snow in 5 hours, the unit rate is 14 inches ÷ 5 hours = 2.8 inches per hour.

Front

What is a ratio?

Back

A ratio is a relationship between two numbers indicating how many times the first number contains the second. For example, the ratio of 12 to 20 can be written as 12:20.

Front

What does it mean for two ratios to be equivalent?

Back

Two ratios are equivalent if they represent the same relationship between numbers. For example, the ratios 3:5 and 12:20 are equivalent.

Front

How do you find an equivalent ratio?

Back

To find an equivalent ratio, you can multiply or divide both terms of the ratio by the same non-zero number. For example, multiplying both terms of 2:3 by 2 gives you 4:6.

Front

If a hamburger costs $6 for 3 pounds, how much does it cost per pound?

Back

To find the cost per pound, divide the total cost by the number of pounds: $6 ÷ 3 pounds = $2 per pound.

Front

If a teacher grades 25 assignments in 20 minutes, how many assignments can he grade in 1 hour?

Back

In 1 hour (60 minutes), he can grade 25 assignments in 20 minutes, so in 60 minutes, he can grade (60 ÷ 20) × 25 = 75 assignments.

Front

What is the formula for calculating a rate?

Back

The formula for calculating a rate is: Rate = Quantity / Time. For example, if you travel 60 miles in 1 hour, your rate is 60 miles/hour.

Front

How do you compare two rates?

Back

To compare two rates, convert them to the same unit and then compare the values. For example, if one rate is 30 miles/hour and another is 45 miles/hour, 45 miles/hour is faster.

Front

What is the relationship between ratios and fractions?

Back

Ratios can be expressed as fractions. For example, the ratio 3:4 can be written as the fraction 3/4.