7th 2-2 Unit Rates with Ratios and Fractions

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 single unit. For example, if a car travels 300 miles in 5 hours, the unit rate is 60 miles per hour.

Front

How do you calculate a unit rate from a fraction?

Back

To calculate a unit rate from a fraction, divide the numerator by the denominator and express the result as a rate per one unit. For example, for 1/5 mile in 1/65 hour, calculate (1/5) ÷ (1/65) = 13.

Front

What is the ratio of boys to girls if there are 4 boys for every 7 girls?

Back

The ratio of boys to girls is 4:7.

Front

If there are 21 girls in a ratio of 4:7, how many boys are there?

Back

To find the number of boys, set up a proportion: 4/7 = x/21. Solving gives x = 12 boys.

Front

How do you compare speeds of different runners?

Back

To compare speeds, calculate the unit rate (miles per hour) for each runner and compare those values. The highest unit rate indicates the fastest runner.

Front

What is the unit rate for running 3.1 miles in 28 minutes?

Back

The unit rate is 3.1 miles / 28 minutes = 0.11 miles per minute.

Front

How do you convert a distance and time into a unit rate?

Back

Divide the distance by the time to find the unit rate. For example, if you run 17 inches in 114 minutes, the unit rate is 17/114 = 0.15 inches per minute.

Front

What is the formula for finding a unit rate?

Back

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

Front

If Noah ran 2 1/2 miles in 3/5 hour, how do you find his speed?

Back

Convert 2 1/2 to an improper fraction (5/2) and divide by 3/5: (5/2) ÷ (3/5) = (5/2) * (5/3) = 25/6 miles per hour.

Front

What is the unit rate for Emily who ran 3 3/4 miles in 5/6 hour?

Back

Convert 3 3/4 to an improper fraction (15/4) and divide by 5/6: (15/4) ÷ (5/6) = (15/4) * (6/5) = 18 miles per hour.