Ratios, Rates, & Unit Rates

Front

What is a ratio?

Back

A ratio is a comparison of two quantities that shows the relative size of one quantity to another, often expressed as 'a to b' or a:b.

Front

What is a rate?

Back

A rate is a specific kind of ratio that compares two different units, such as miles per hour or dollars per pound.

Front

What is a unit rate?

Back

A unit rate is a rate in which the second quantity is one unit, such as 60 miles per hour or $2 per item.

Front

How do you find the unit rate from a total cost and quantity?

Back

To find the unit rate, divide the total cost by the quantity. For example, if $3.75 is spent for 3 pounds, the unit rate is $3.75 ÷ 3 = $1.25 per pound.

Front

What is the simplest form of a ratio?

Back

The simplest form of a ratio is when both quantities are divided by their greatest common factor, making the numbers as small as possible.

Front

If there are 22 dogs and 12 lizards, what is the ratio of dogs to lizards in simplest form?

Back

The ratio of dogs to lizards is 22:12, which simplifies to 11:6.

Front

How do you convert a ratio to a fraction?

Back

To convert a ratio to a fraction, write the first quantity as the numerator and the second quantity as the denominator. For example, the ratio 4:5 becomes 4/5.

Front

What is the formula to calculate speed (unit rate of distance)?

Back

Speed = Distance ÷ Time. For example, if a car travels 320 miles in 8 hours, the speed is 320 ÷ 8 = 40 miles per hour.

Front

How do you express a ratio of part to whole?

Back

To express a ratio of part to whole, divide the part by the total. For example, if there are 4 nickels out of 12 total coins, the ratio is 4:12.

Front

What is the unit rate if a person earns $90 in 5 hours?

Back

The unit rate is $90 ÷ 5 = $18 per hour.