Transcript M6U2L1ratioratespresentation

INTRODUCTIONS TO UNIT
2
Ratios, Rates and Unit Rates
Ratios and Rates
Ratios
Ratios continued
Compares two quantities ,
(numbers, amounts) using division
Help compare:
Part to part (boys to girls)
Part to whole (boys to students)
Whole to part (Total students to
boys)
Can be written 3 ways
3 to 4, or 3:4 or
3
4
Always reduce your fractions!
Order matters
Ratios can be written from
pictures or from tables
Ratios
1. Write a ratio three ways comparing the oranges to strawberries (Order
matters)
4 to 3 ,
4: 3
or 4/3
2. Write a ratio three ways comparing strawberries to total fruit
3 to 11
3:11
or
𝟑
𝟏𝟏
3. Write a ratio comparing total fruit to pineapples
𝟏𝟏
11 to 4
11:4
or 𝟒
Use the table to write a ratio 3 ways
Lady Gaga’s Accessories
Accessories
How many
Sunglasses
25
1. What is the ratio of her wigs to
her shoes
45 to 50, 45 : 50,
𝟒𝟓
𝟓𝟎
=
𝟗
𝟏𝟎
Earrings
30
Wigs
45
Scarves
35
2. What is the ratio of total
Shoes
50
accessories to scarves? (Hint add
the total number of accessories first)
How do you wake Lady Gaga up?
You poke her face!!! HAHAHA
185 to 35, 185: 35
𝟏𝟖𝟓
𝟑𝟓
=
𝟑𝟕
𝟕
Rates

A rate is a special ratio, compares 2 quantities that
have different units of measure
Examples:

3 shirts for $9

16 gallons of gas for $64

Sue drove 100 miles in 2 hours

Unit Rates



A unit rate is a special rate comparing something to
ONE unit only
Why do we care about Unit Rate? It helps us decide
what is cheaper!!!
Can be expressed using the word per
Unit Rate – what is the better buy?
4 shirts cost $8.00



Find the cost of one shirt
by dividing the cost by
the number of shirts
$8.00 ÷ 4
1 shirt costs $2.00
6 shirts cost $18.00

Find the cost of one shirt by
dividing the cost by the
number of shirts

$18.00 ÷ 6

1 shirt costs $3.00
What’s the better buy? 4 shirts for $8.00 because each shirt costs $2.00
What is the better buy – a 6oz bag of flour for
$4.80 or a 12 oz bag for $6.00?
12 ounces of flour costs $6.00
6 ounces of flour costs $4.80

Figure out the cost of ONE
ounce

Figure out the cost of ONE
ounce

Divide $4.80 by 6

Divide $6.00 by 12

6 4.80

12 6.00

.80 per ounce

.50 per ounce
What’s the better buy?
It’s cheaper to buy the 12 ounces of flour because it costs less per ounce.
More Practice….
Write each ratio 3 ways
1. Soccer balls to tennis balls
𝟒
𝟐
4 to 6, 4 : 6 , =
𝟔
𝟑
2. Footballs to tennis balls
5 to 6, 5: 6 ,
𝟓
𝟔
3. Tennis balls to footballs
𝟔
6 to 5, 6:5,
𝟓
4. Why is the ratio of footballs to tennis balls different from the ratio of tennis balls to footballs?
Because order matters. In #2, footballs came first and in #3, tennis balls came first
More Practice…….
You can buy 2 ice cream cones for $3.00 or 4 ice cream cones for
$7.00. Which is the better buy?
2 cones = $1.50 per cone. 4 cones = $1.75 per cone.
It is cheaper to buy 2 cones
 Jason makes $36.00 for 6 hours of work and Michael makes
$24.00 for 3 hours of work. Who makes more money per hour?
Jason makes $6 per hour and Michael makes $8 per hour.
Michael makes more money
 A Hummer can get 60 miles for 5 gallons of gas and a Camry can
get 40 miles on 2 gallons of gas. How many miles does each car
get per gallon? Which car gets more miles per gallon?
Hummer = An average of 12miles/gallon. Camry = An average
of 20 miles/gallon. Camry gets more miles per gallon
