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eToolkitePresentations Interactive Teacher’s
Lesson Guide
Algorithms Practice
EM FactsWorkshop Game™
AssessmentManagement
Family Letters
CurriculumFocal Points
Common Core State Standards
926 Unit 12 Rates
Advance Preparation
Teacher’s Reference Manual, Grades 4–6 pp. 13, 64 – 68, 160, 168, 169
Key Concepts and Skills• Find multiples.
[Number and Numeration Goal 3]
• Multiply and divide decimals by whole
numbers.
[Operations and Computation Goal 4]
• Use repeated addition and scaling
to model multiplication problems.
[Operations and Computation Goal 7]
• Analyze and interpret data.
[Data and Chance Goal 2]
• Use patterns and rules to solve rate
problems.
[Patterns, Functions, and Algebra Goal 1]
Key ActivitiesStudents calculate the unit prices of various
products. They calculate and compare the
unit prices of two products to decide which
is the better buy.
Ongoing Assessment: Informing Instruction See page 929.
Key Vocabularyconsumer � products � services �
comparison shopping � unit price
MaterialsMath Journal 2, pp. 319 and 320
Study Link 12�3
Math Masters, p. 454 (optional)
calculator � slate
Playing Name That NumberStudent Reference Book, p. 254
Math Masters, p. 489
per partnership: complete deck of
number cards (the Everything Math
Deck, if available)
Students practice representing
numbers in different ways.
Ongoing Assessment: Recognizing Student Achievement Use Math Masters, page 489. [Patterns, Functions, and Algebra Goal 3]
Converting Units of MeasureMath Journal 2, pp. 319A and 319B
Students convert among units of
measure.
Math Boxes 12�4Math Journal 2, p. 321
Students practice and maintain skills
through Math Box problems.
Study Link 12�4Math Masters, p. 345
Students practice and maintain skills
through Study Link activities.
READINESS
Finding Unit PricesMath Masters, pp. 346 and 428
coins
Students use a concrete model to determine
unit prices.
ENRICHMENTTesting Productsproducts to test
Students test products and then analyze and
interpret the data.
Teaching the Lesson Ongoing Learning & Practice
132
4
Differentiation Options
�
Comparison Shopping: Part 1
Objectives To introduce calculating the unit price for a product;
and to provide practice comparing unit prices and identifying
information needed for comparison shopping.
a
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1 Teaching the Lesson
� Math Message Follow-Up WHOLE-CLASSDISCUSSION
(Math Journal 2, p. 319)
Students share their definitions of the word consumer. Sample answer: A person who acquires products or uses services
Pose questions such as the following, and list students’ responses on the board.
● What are some products and services you have used recently? Sample answers: Products: food, clothing, school supplies; Services: public transportation, school, the postal service, utilities such as the telephone or electricity
● What are some of the qualities of a smart consumer? Sample answers: Makes thoughtful decisions based on the quality, price, and effect of the product or service on the environment, as well as on personal needs and taste
● What information might you want to know before choosing a baseball camp? Sample answers: The qualifications of the counselors, the types of activities offered, the location of the camp, the cost
● How would you go about getting the information you need to select the best product? Sample answers: Ask people who have used the products, read articles about the products in consumer magazines, compare prices. This kind of research is called comparison shopping.
Product TestingLESSON
12�4
Date Time
Some publications ask their readers to test many different kinds of products. The results of the
tests are then published to help readers make wise buying decisions. One example is the former
Consumer Reports for Kids Online. It featured articles previously published in Zillions, a child’s
version of Consumer Reports. In one test, 99 readers field tested several backpack models. The
readers considered fit, back friendliness, and comfort as they tried to decide which brand was
the best buy. In another test, a team of young people compared 40 brands of jeans in their search
for a brand that would not shrink in length.
When a reader wrote to complain about a board game she bought, the staff sent board
games to young people in every part of the country. Testers were asked to play each
game several times and then to report what they liked and disliked about the game.
1. If you were testing a board game, what are some of the features you would look for?
2. When readers of the magazine tested backpacks, they considered fit, back friendliness, and
comfort in determining the best one. Which of these factors is the most important to you? Why?
3. What is a consumer? Be prepared to share your definition with the class.
Answers vary.
309-328_EMCS_S_MJ2_G4_U12_576426.indd 319 2/18/11 9:18 AM
Math Journal 2, p. 319
Student Page
Lesson 12�4 927
Getting Started
Math MessageRead and complete journal page 319.
Study Link 12�3 Follow-UpHave small groups compare answers.
Mental Math and ReflexesPose measurement conversion problems. Suggestions:
1 hour is 60 minutes. How many minutes are in
2 hours? 120
4 hours? 240
7 hours? 420
1 pound is 16 ounces. How many ounces are in
2 pounds? 32
30 pounds? 480
100 pounds? 1,600
1 kilogram is 1,000 grams. How many grams are in
3 1
__ 2 kilograms? 3,500
7 1
__ 4 kilograms? 7,250
15 1
__ 2 kilograms 15,500
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928 Unit 12 Rates
� Introducing Unit Prices WHOLE-CLASS ACTIVITY
(Math Masters, p. 454)
NOTE Although the sequence of lessons on unit pricing focuses on the
arithmetic of buying products and services, it is also important to discuss the
more general aspects of what it means to be a consumer.
Throughout the sequence of lessons on unit pricing, remind students that
comparison shopping is not simply a matter of determining which of several
comparable products or services is the cheapest. There are other important
factors that enter into making wise decisions.
Consumer Link The unit price is the cost of an item per unit of measure. Give several examples and write them in
rate tables so that students will understand that unit prices are rates. To support English language learners, help students make connections between the terms unit fraction and unit rate from prior lessons and the term unit price. Suggestions:
● A 10-pound bag of potatoes costs $5.00. The unit price is the cost of 1 pound. $0.50
● A package of 6 pens costs $4.20. The unit price is the cost of 1 pen. $0.70
● A dozen bagels cost $3.60. The unit price is the cost of 1 bagel. $0.30
Ask how the unit price is calculated from the cost information that is given. Divide the cost by the number of units or items. For example, $5.00 ÷ 10 = $0.50, $4.20 ÷ 6 = $0.70, and $3.60 ÷ 12 = $0.30. Explain that finding the unit price is like solving an equal-sharing problem: Division is used to find the cost of each unit, item, or share.
Now pose several practice problems on comparison shopping. Work through these as a class, and encourage students to use calculators. Calculate unit prices for similar items, and then compare these unit prices to determine which item is the better buy. Point out that unit prices are not easily compared unless they are for the same unit. (For example, $3.20/1 lb and $0.10/1 oz are not easily compared, but $0.20/1 oz and $0.10/1 oz are.)
ELL
Dollars 0.50 5.00
Pounds 1 10
Dollars 0.70 4.20
Pens 1 6
Dollars 0.30 3.60
Bagels 1 12
Converting Units of MeasureLESSON
12� 4
Date Time
315
1 pound (lb) = 16 ounces (oz)
1 ton (T) = 2,000 pounds (lb)
Complete the conversions between ounces, pounds, and tons.
Write the information you needed to make the conversion.
1. 5 lb = 80 oz 1 lb = 16 oz
2.1__2 lb = 8 oz 1 lb = 16 oz
3. 129 lb = 2,064 oz 1 lb = 16 oz
4. 2 T = 4,000 lb 1 T = 2,000 lb
5. 6 1__4 T = 12,500 lb 1 T = 2,000 lb
6. 112 oz = 7 lb 1 lb = 16 oz
7. 20,000 lb = 10 T 1 T = 2,000 lb
8. 4,240 oz = 265 lb 1 lb = 16 oz
9. 3,000 lb =1 1 _
2 T 1 T = 2,000 lb
10. 1 1__4 lb = 20 oz 1 lb = 16 oz
Complete the table.
11. Ounces Pounds Tons
160,000 10,000 5
304,000 19,000 9.5
16,000 1,000 1 _ 2
319A-319B_EMCS_S_MJ2_G4_U12_576426.indd 319A 3/16/11 1:04 PM
Math Journal 2, p. 319A
Student Page
Unit PricesLESSON
12�4
Date Time
Solve the unit price problems below. Complete the tables if it is helpful to do so.
1. A 12-ounce can of fruit juice costs 60 cents. The unit price is per ounce.
47
$0.05
Dollars
Ounces 1 3 6 12
0.05 0.15 0.30 0.60
Dollars
Pounds 1 2 3 4
0.29 0.58 0.87 1.16
Dollars
Pounds 1 2 3 4 5
0.38 0.76 1.14 1.52 1.90
Dollars
Pounds 1 2 3 4 7
7.00 14.00 49.00 66.5028.0021.00
2. A 4-pound bunch of bananas costs $1.16. The unit price is per pound.$0.29
$0.383. A 5-pound bag of apples costs $1.90. The unit price is per pound.
4. Three pounds of salmon cost $21.00.
a. The unit price is per pound.
b. What is the cost of 7 pounds of salmon?
c. What is the cost of 9 1
_
2 pounds of salmon?
$7.00$49.00$66.50
9 1
_
2
5. Energy granola bars come in packages of 25 and cost $3.50 per package. Super granola bars
come in packages of 30 and cost $3.60 per package. Which is the better buy? Explain.
It depends. Super bars are $0.12 each, and Energy bars are
$0.14 each. So Super bars are cheaper per bar. However, an
Energy bar may be much larger than a Super bar.
Try This
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Math Journal 2, p. 320
Student Page
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Date Time
12. Record measurement equivalents in the two-column tables below.
a. Feet Inches
1 12
2 24
3 36
4 48
5 60
b. Liters Milliliters
1 1,000
2 2,000
3 3,000
4 4,000
5 5,000
c. Minutes Seconds
1 60
2 120
3 180
4 240
5 300
Find the equivalent measures.
13. a. 6 km = 6,000 m b. 2 L = 2,000 mL
c. 6 yd = 18 ft d. 3.25 L = 3,250 mL
e. 5 1 _ 2 kg = 5,500 g f. 8 1
_ 2 hr = 510 min
g. What do you notice when you convert from a larger unit to a
smaller unit (such as from L to mL)?
Sample answer: You need to multiply to
find the equivalent measure.
14. a. 4,000 g = 4 kg b. 200 cm = 2 m
c. 875 mL = 0.875 L d. 660 sec = 11 min
e. 1,500 mL = 1.5 L f. 156 in. = 13 ft
g. What do you notice when you convert from a smaller unit to a
larger unit (such as from mL to L)?
Sample answer: You need to divide to
find the equivalent measure.
Sample answers: Sample answers:
Converting Units of Measure continuedLESSON
12�4 315
319A-319B_EMCS_S_MJ2_G4_U12_576426.indd 319B 3/30/11 12:58 PM
Math Journal 2, p. 319B
Student Page
Lesson 12�4 929
321
Math Boxes LESSON
12�4
Date Time
5. Add blocks to the bag so it is likely that
Arjan will pick a C block without looking.
CC C CA B C
A B C
Sample answer:
1. a. Complete the table.
3. Find the solution of each open sentence.
a. t + 30 = -120 t =
b. 75 + n = 20 n =
c. 16 + b = 0 b =
d. c + (-61) = -97 c =
148
47
80
2. Complete.
a. 7 gal = 28 qt
b. 8 L = 8,000 mL
c. 0.25 L = 250 mL
d. 6 gal 1 qt = 25 qt
e. 3 qt 1 pt = 14 c
b. How many inches are in 329 yards?
inches11,844
-55
-16
-36
-150
137
149
38 39
6. Calculate.
a. 10% of 520 = 52
b. 5% of 180 = 9
c. 40% of 10 = 4
d. 50 % of 30 = 15
e. 40 % of 35 = 14
f. 40 % of 95 = 38
15
Number of Inches
72
540
Number of Yards 1 2 9 12
36 324432
4. Which one of the names below is not a
name for 3.16? Fill in the circle next to
the best answer.
A 4.8 - 1.64
B 15.8 / 5
C 2.47 ∗ 6
D 2.5 + 0.66
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Math Journal 2, p. 321
Student Page
Suggestions:
� Lightbulbs
Brand A: package of 4 bulbs for $2.08
Brand B: package of 6 bulbs for $3.00
Brand A: $0.52/1 bulb; Brand B: $0.50/1 bulb; Brand B is the better buy.
� Crackers
Brand A: 1-pound box for $2.40
Brand B: 24-ounce box for $3.84
Brand A: $0.15/1 oz; Brand B: $0.16/1 oz; Brand A is the better buy.
� Calculating and Comparing PARTNER ACTIVITY
Unit Prices(Math Journal 2, p. 320)
Have partners complete Problems 1–5 on journal page 320.
Ongoing Assessment: Informing Instruction
Watch for students who assume that the lower-cost package of Energy granola
bars in Problem 5 is the better buy. Have students compare quantities and
explain that even though the price of the package may be lower, the price per
granola bar may be higher because there are not as many bars in the package
or the size of the bars is smaller.
2 Ongoing Learning & Practice
� Playing Name That Number PARTNER ACTIVITY
(Student Reference Book, p. 254; Math Masters, p. 489)
Students play Name That Number to practice representing numbers in different ways. See Lesson 2-2 for additional information.
Ongoing Assessment: Math Masters
Page 489Recognizing Student Achievement
Use Math Masters, page 489 to assess students’ ability to insert grouping
symbols to make true number sentences. Students are making adequate
progress if they are able to use parentheses in number sentences to show
combinations of numbers and operations that name the target numbers. Some
students may be able to use nested parentheses in their number sentences.
[Patterns, Functions, and Algebra Goal 3]
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�
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930 Unit 12 Rates
STUDY LINK
12�4 Unit Prices
Name Date Time
Solve the unit price problems below. Complete the tables if it is helpful to do so.
1. A 12-oz bag of pretzels costs 96 cents. The unit price is 8 cents
per ounce.
Dollars 0.08 0.24 0.72 0.96
Ounces 1 3 9 12
Dollars 0.35 0.70 1.05 1.40
Liters 1 2 3 4
Dollars 0.69 1.38 2.07
Rolls 1 2 3
2. A package of 3 rolls of paper towels costs $2.07. The unit price is $0.69
per roll.
3. A 4-liter bottle of water costs $1.40. The unit price is $0.35 per liter.
4. Choose 4 items from newspaper ads. In the table below, record the name,
price, and quantity of each item. Leave the Unit Price column blank.
Item Quantity Price Unit Price
Golden Sun 24 ounces $2.99 12.4 cents per ounce Raisins
Answers vary.
Practice
Name the factor pairs for each number.
5. 12 1, 12; 2, 6; 3, 4 6. 50 1, 50; 2, 25; 5, 10
47
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Math Masters, p. 345
Study Link Master
� Converting Units of Measure INDEPENDENTACTIVITY
(Math Journal 2, pp. 319A and 319B)
Students convert among units of weight, capacity, length, and time. They look for patterns in how they make the conversions.
� Math Boxes 12�4 INDEPENDENTACTIVITY
(Math Journal 2, p. 321)
Mixed Practice Math Boxes in this lesson are linked with Math Boxes in Lessons 12-2 and 12-6.
� Study Link 12�4 INDEPENDENTACTIVITY
(Math Masters, p. 345)
Home Connection Students calculate unit prices. They also look for supermarket ads in newspapers and record the information contained in four of them. In Lesson 12-5, students will calculate the unit prices of these items.
3 Differentiation Options
READINESS PARTNER ACTIVITY
� Finding Unit Prices 5–15 Min
(Math Masters, pp. 346 and 428)
To explore unit prices using a concrete model, have students determine the unit prices for items sold during a summer stock-up sale. Encourage students to use bills (Math Masters, page 428) and coins to act out dividing the stock-up price by the number of items to find the unit price.
ENRICHMENT PARTNER ACTIVITY
� Testing Products 30+ Min
To apply students’ ability to analyze and interpret data, have students create guidelines for testing a product such as colored markers. They may want to consider factors such as brightness, cost, and drying time. Encourage students to use a scale to rate each criterion for each brand. For example: 4 = excellent, 3 = good, 2 = not so good, 1 = poor. Have students test three brands of the chosen product using their guidelines. Students should tally and report their findings with a chart or graph.
LESSON
12�4
Name Date Time
Stock-Up Sale
Party Town is having a summer stock-up sale. The ad below shows the original price of each
item and the sale price if you buy a certain number of items. Use bills and coins to help you
find the stock-up price per item.
Party Music CDs
$8.00 each
1.
You pay $5.00
per CD.Stock-Up Price: Buy 5 for $25.00.
String in a Can
$3.00 each
2.
You pay $2.00
per can.Stock-Up Price: Buy 8 for $16.00.
3.
Stock-Up Price: Buy 12 for $14.40.
4.
Stock-Up Price: Buy 3 for $29.97.
Glow bracelets
$2.50 each
5.
Stock-Up Price:
Buy 6 for $10.50.
Party Hats
$9.99 for a package of 45
6.
Stock-Up Price: Buy
4 packages for $19.96.
Mylar Balloon
$1.99 each
Piñata
$14.99 each
You pay $1.20
per balloon.
You pay $1.75
per bracelet.
You pay $9.99
per piñata.
You pay $4.99
per package.
339-357_EMCS_B_MM_G4_U12_576965.indd 346 2/14/11 5:04 PM
Math Masters, p. 346
Teaching Master
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