4.1 D - Unit Rates Lesson 4-1 D Mrs. Wilson

A rate is a RATIO that compares two things that have DIFFERENT units! What does rate mean? A rate is a RATIO that compares two things that have DIFFERENT units! Ex: Students per Bus OR Miles per Hour The unit rate is the rate for one unit of a given quantity. Unit rates have a denominator of 1. The word PER means 1 !!!!

Going from rate to Unit rate 150 heartbeats in 2 minutes Rate: 150 heartbeats See how there are 2 different units of measure? 2 minutes just DIVIDE to get the Unit Rate!!! 150 ÷ 2 = 75 heartbeats per minute. You can also write it as… 75 heartbeats / minute

Find the Unit Rate Amy can read 88 pages in 4 hours. What is the unit rate? (How many pages can she read per hour?) 88 ÷ 4 = 22 So… 22 pages per hour or 22 pgs / hr 88 pages 4 hours 1 hr Notice that hours turns to 1…that is the number you divide by!

Not all rates will be even numbers! It is $30 for 4 t-shirts. What is the unit rate? 30 ÷ 4 = 7.5 You have to add a decimal and a zero!! How much $ is this? $30 4 shirts 1 shirt $7.50 for each shirt!

Sometimes you know the unit rate already… Joe’s car goes 20 miles per gallon of gasoline. How far can it go on 8 gallons of gasoline? *Per Means 1. Here’s what it looks like! x 8 20 miles = 1 gallon 8 gallons x 8 20 x 8 = 160. Joe’s car can go 160 miles on 8 gallons of gas.

Sometimes you know the unit rate already… It costs $15.50 per student for the trip. If there are 20 students going, how much will the total be? *Per Means 1. Here’s what it looks like! x 20 $15.50 = 1 student 20 students x 20 15.50 x 20 = 310. So it will cost $310 for 20 students to go.

If you need to FIND a UNIT rate, you DIVIDE It’s easy to remember: If you need to FIND a UNIT rate, you DIVIDE If you already KNOW the Unit Rate, you MULTIPLY If you are ever unsure WHICH number to divide by, find the measure that will become a 1. This measure is what you divide by!!!