Rate/Unit Rate

What is it? A rate is a special ratio that compares two values with different units. Rates sometimes use the words per and for instead of the word to. Rates can be simplified.

Rate or No Rate (examples) 16 girls to 24 students 55 miles per hour 4 lemons for $ miles per gallon 75 out of $ tickets for 50

What is it? A unit rate is a rate whose denominator is 1 when it is written as a fraction. To change a rate to a unit rate, first write the rate as a fraction and then divide both the numerator and denominator by the denominator.

Finding Unit Rates Example #1 During exercise, Abby’s heart beats 675 times in 5 minutes. How many times does it beat per minute? ◦Write a rate that compares the heart beats and time. ◦Divide the numerator and denominator by 5. ◦Simplify.

Example #2 To make 4 large pizza pockets, Paul needs 14 cups of broccoli. How much broccoli does he need for 1 large pizza pocket? ◦Write a rate that compares. ◦Divide the numerator and denominator by the denominator. ◦Simplify.

Rate of Speed An average rate of speed is the ratio of distance traveled to time. The ratio is a rate because the units being compared are different.

Example #3 Finding Average Speed The Lawsons want to drive 288 miles to Rainbow Falls in 6 hours. What should their average speed be in miles per hour? ◦Write the rate as a fraction. ◦Divide the numerator and denominator by the denominator.