Ratios and Rates

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, showing how many times one value contains or is contained within the other.

Front

What is a rate?

Back

A rate is a specific kind of ratio that compares two different units, such as speed (miles per hour) or price per item.

Front

How do you find the unit rate?

Back

To find the unit rate, divide the total quantity by the number of units. For example, if 15 hamburgers cost $75, the unit rate is $75 ÷ 15 = $5 per hamburger.

Front

If 4 bars of soap cost $5, how much do 8 bars cost?

Back

$10 (Since 8 bars is double the amount of 4 bars, the cost will also double.)

Front

If Mrs. Campbell knits 3 inches of a scarf per day, how many days will it take her to knit 24 inches?

Back

8 days (24 inches ÷ 3 inches per day = 8 days.)

Front

What is an equivalent ratio?

Back

An equivalent ratio is a ratio that expresses the same relationship between two quantities, even if the numbers are different. For example, 2:3 and 4:6 are equivalent ratios.

Front

If 4 out of every 5 seeds will grow, how many seeds will grow if 40 seeds are planted?

Back

32 seeds (40 seeds × 4/5 = 32 seeds.)

Front

Evan made 2 out of every 3 free throws. If he attempted 12 free throws, how many did he make?

Back

8 free throws (12 free throws × 2/3 = 8 free throws.)

Front

What is the formula to calculate a ratio?

Back

The formula to calculate a ratio is: Ratio = Quantity A : Quantity B.

Front

How do you express a rate as a fraction?

Back

A rate can be expressed as a fraction by placing the first quantity in the numerator and the second quantity in the denominator. For example, if a car travels 60 miles in 1 hour, the rate is 60 miles/1 hour.