Post on 29-Dec-2015
01/18/11 Unit Rates
Today’s Plan:-Warm-Up & Test Results-Unit Rates Lesson-Unit Rates Assignment
Learning Target: I will calculate and compare unit rates.
A shopping cart contains 35 cans of soda, 16 oranges, 17 carrots, and 29 cookies. Write ratios for each of the following.
1. Carrots to oranges
2. Cookies to cans of soda
3. Oranges to carrots
4. Cookies to oranges and soda
Warm Up
01/18/11 Unit Rates
Today’s Plan:-Warm-Up & Test Results-Unit Rates Lesson-Unit Rates Assignment
Learning Target: I will calculate and compare unit rates.
Test Results
01/18/11 Unit Rates
Today’s Plan:-Warm-Up & Test Results-Unit Rates Lesson-Unit Rates Assignment
Learning Target: I will calculate and compare unit rates.
Divide. Round answers to the nearest tenth.
1. 2.
3. 4.
23.3 3.5
23.8 23.9
420 18
73 21
380 16
430 18
Now arrange the original ratios from least to greatest.
Compare and Order Ratios
01/18/11 Unit Rates
Today’s Plan:-Warm-Up & Test Results-Unit Rates Lesson-Unit Rates Assignment
Learning Target: I will calculate and compare unit rates.
Unit Rates
If the measure of the second quantity in a rate or ratio is one unit, then the rate is a unit rate.
01/18/11 Unit Rates
Today’s Plan:-Warm-Up & Test Results-Unit Rates Lesson-Unit Rates Assignment
Learning Target: I will calculate and compare unit rates.
An aspect ratio describes a screen by comparing its width to its height.
Movie and television screens range in shape from almost perfect squares to wide rectangles.
Common aspect ratios are 4:3, 37:20, 16:9, and 47:20.
Additional Example 1A: Ordering Ratios
A. Order the ratios 4:3, 23:10, 13:9, and 47:20 from the least to greatest.
4:3 =
23:10 =
13:9 =
47:20 =
4 3
4 3
Divide. = 1.3 1
= 1.3
23 10
13 947 20
= 1.4
= 2.3
= 2.35
The ratios in order from least to greatest are 4:3, 13:9, 23:10, and 47:20.
The decimals in order are 1.3, 1.4, 2.3, and 2.35.
A. Order the ratios 2:3, 35:14, 5:3, and 49:20 from the least to greatest.
Try This: Example 1A
2:3 =
35:14 =
5:3 =
49:20 =
2 3
2 3
Divide. = 0.6 1
= 0.6
35 14
5
3 49 20
= 1.6
= 2.5
= 2.45
The ratios in order from least to greatest are 2:3, 5:3, 49:20, 35:14.
The decimals in order are 0.6, 1.6, 2.45, and 2.5.
Find the unit rates and write them in both fraction and word forms.
Additional Example 2A: Writing Rates and Unit Rates
Course 2
5-1 Ratios and Rates
A. Gordon memorized 560 vocabulary words in 28 days.
560 words28 days
Rate in fraction form
560 ÷ 28 28 ÷ 28
= 20 words1 day
Unit rate in fraction form
Gordon memorized 20 words per day.
Unit rate in word form
Find the unit rates and write them in both fraction and word forms.
Additional Example 2B: Writing Rates and Unit Rates
Course 2
5-1 Ratios and Rates
B. Pete added 12 ounces of chocolate chips to a recipe that yielded 48 cookies.
12 oz 48 cookies
Rate in fraction form
12 ÷ 4848 ÷ 48
= 0.25 oz1 cookie
Unit rate in fraction form
There is 0.25 ounce of chocolate chips per cookie.
Unit rate in word form
Find the unit rates and write them in both fraction and word forms.
Try This: Example 2A
Course 2
5-1 Ratios and Rates
A. Harold could jog 1,000 meters in 5 minutes.
1,000 m5 min
Rate in fraction form
1,000 ÷ 5 5 ÷ 5
= 200 m1 min
Unit rate in fraction form
Harold jogged 200 meters per minute.
Unit rate in word form
Find the unit rates and write them in both fraction and word forms.
Try This: Example 2B
Course 2
5-1 Ratios and Rates
B. Yvonne added 3 ounces of blueberries to a recipe that made 12 muffins.
3 oz 12 muffins
Rate in fraction form
3 ÷ 1212 ÷ 12
= 0.25 oz1 muffin
Unit rate in fraction form
There is 0.25 ounce of blueberries per muffin.
Unit rate in word form
Honey-lemon cough drops come in packages of 30 drops per 10-ounce bag. Cherry cough drops come in packages of 24 drops per 6-ounce bag. Compare the ratio of drops per ounces for each bag of cough drops.
Additional Example 3: Simplifying Ratios to Make Comparisons
Course 2
5-1 Ratios and Rates
Honey-lemon Cherry
Ounces 10 6
Drops 30 24
Honey-lemon: dropsounces
= 3010
= 31
Cherry: dropsounces
= 246
= 41
41
is greater than 31
.
The ratio of drops to ounces is greater in the bag of cherry cough drops.
Simplify the ratio.
Simplify the ratio.
Jawbreakers come in small packages of 20 per 5 ounce package and large packages of 24 per 8 ounce package. Compare the ratio of jawbreakers per ounce for each of the packages.
Try This: Example 3
Course 2
5-1 Ratios and Rates
Large Small
Ounces 8 5
Jawbreaker 24 20
Large:jawbreaker ounces
= 248
= 31
Small: jawbreaker ounces
= 205
= 41
41
is greater than 31
.
The ratio of jawbreakers to ounces is greater in the small package.
Simplify the ratio.
Simplify the ratio.
Insert Lesson Title Here
Course 2
5-1 Ratios and Rates
Find the unit rate and write it in both
fraction and word form. There are 220 calories in 5 crackers.
44 calories 1 cracker
, 44 calories per cracker
01/18/11 Unit Rates
Today’s Plan:-Warm-Up & Test Results-Unit Rates Lesson-Unit Rates Assignment
Learning Target: I will calculate and compare unit rates.
Unit price is a unit rate used to compare costs per item. With unit price, $ go on the top of the ratio.
$3 2 bags goldfish = $1.50 per bag goldfish
Pens can be purchased in a 5-pack for $1.95 or a 15-pack for $6.20. Which is the better buy?
Additional Example 3A: Finding Unit Prices to Compare Costs
Divide the price by the number of pens.
price for packagenumber of pens
$1.955
= $0.39
price for packagenumber of pens
= $6.2015
$0.41
The better buy is the 5-pack for $1.95.
Golf balls can be purchased in a 3-pack for $4.95 or a 12-pack for $18.95. Which is the better buy?
Try This: Example 3A
Divide the price by the number of balls.
price for packagenumber of balls
$4.953
= $1.65
price for packagenumber of balls
= $18.9512
$1.58
The better buy is the 12-pack for $18.95.
Jamie can buy a 15oz jar peanut butter for $2.19 or a 20 oz jar for $2.78. Which is the better buy?
Additional Example 3B: Finding Unit Prices to Compare Costs
$2.1915
= $0.15
= $2.7820
$0.14
The better buy is the 20-oz jar for $2.78.
price for jarnumber of ounces
price for jarnumber of ounces
Divide the price by the number of ounces.
Try This: Example 3B
John can buy a 24 oz bottle of ketchup for $2.19 or a 36 oz bottle for $3.79. Which is the better buy?
$2.1924
= $0.09
= $3.7936
$0.11
The better buy is the 24-oz jar for $2.19.
price for bottlenumber of ounces
price for bottlesnumber of ounces
Divide the price by the number of ounces.