Transcript Unit Rates

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
2 minutes
are 2 different
units of
measure?
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
88 pages
4 hours
So…
1 hr
Notice that hours turns to 1…that is
the number you divide by!
22 pages per hour
or
22 pgs / hr
NOT ALL RATES WILL BE EVEN
NUMBERS!
It is $30 for 4 t-shirts. What is the unit rate?
$30
4 shirts
30 ÷ 4 = 7.5
1 shirt
You have to add a
decimal and a zero!!
How much $ is this?
$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!
x8
20 miles
1 gallon
=
8 gallons
x8
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.
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!!!