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Math on the Spot Video Tutor Online Assessment

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Soar to Success Math Online Intervention

iTools Virtual Manipulatives

Digital ManagementCenter organizes program resources by TEKS!

Interactive Student Edition provides students

with an interactive learning environment!

Resources

e

Texas Essential Knowledge and Skills

Personal Financial Literacy—3.9.B Describe the relationship between the availability or scarcity of resources and how that impacts cost

Also 3.2.D

MATHEMATICAL PROCESSES3.1.A Apply mathematics to problems3.1.F Analyze mathematical relationships

Are You Ready?Access Prior KnowledgeUse the Are You Ready? 20.2 in the Assessment Guide to assess students’ understanding of the prerequisite skills for this lesson.

Vocabularyresources

Go to Multimedia eGlossary at thinkcentral.com

20.2 Cost of Resources How does the availability of resources affect their cost?Essential Question?

Lesson OpenerMaking ConnectionsInvite students to tell you what they know about prices.

What prices do you know? (examples: school lunch, baseball glove, video game, etc.) Do the prices for things always stay the same? (No.) Why do you think some things have a higher price than other things?

Using the Digital LessonYou may want to help students visualize the number of kites made using cubes to represent thousands.

Learning TaskWhat is the problem the students are trying to solve? Connect the story to the problem.

• How many orange kites were made? Purple? Green? Red? (20,000 orange, 25,000 purple, 25,000 green, 15,000 red)

• How much did the orange kites cost? Purple? Green? ($15 for orange, $12 for purple, $12 for green)

• Which color kites were made most? (Purple and green)

• Which color kite costs the least amount of money? (Purple and green)

Literacy and Mathematics Choose one or more of the following activities.

• Ask the students to come up with a list of reasons why the manufacturer might have made fewer red kites.

• Have the students make up a story about the kite fliers that might meet each other.

How does the availability of resources affect their

cost ?

Lesson 20.2 667A

Unlock the ProblemUnlock the Problem

Mathematical ProcessesMath Talk

Essential Question?

Name

Ellen collects character toys. The toys come in sets named by

colors. Some sets are hard to find because the toymaker does not

make many of them. Resources are things that are produced and

used. When many toy sets are made, the resources are plentiful.

When few toy sets are made, the resources are scarce.

Resources and Cost

Toy Set Color Blue Orange Red Purple Green

Number Made 50,000 50,200 500 50,350 50,850

Cost per Set $32 $30 $99 $29 $28

Order the toy sets from the most to the least made.

___________

The toymaker made 50,000 or more of all the toy sets except

for the _ set. Only _ red sets were made.

Round each cost to the nearest ten dollars.

___________

Most toy sets cost about _, but the _ set costs about _.

How does the number of toy sets made relate to the cost

of the toy set?

When many toy sets are available, the cost for each set

is _ (high, low).

When fewer toy sets are available, the cost for each set

is _ (high, low).

Personal Financial Literacy—3.9.B Also 3.2.D

MATHEMATICAL PROCESSES3.1.A, 3.1.F

20.2 Cost of Resources

How does the availability of resources affect their cost?

If the toymaker makes only 100 toys sets in a

new color, do you think the cost will be more than $99 or less than

$99? Explain.

green, purple, orange, blue, red

blue: $30; orange: $30; red: $100; purple: $30; green: $30

red 500

$30 $100

low

high

red

Math Talk: Possible explanation: I think the cost will be more than $99 because the new set would be even harder to fi nd than the red set. If there is less of a product available, its cost goes up.

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Module 20 667

Language SupportELL

English Language Learners

ELPS 1.B.1, 2.E.3, 3.D.1

Strategy: Model Language• Students can learn correct pronunciation and sentence structure by

repeating words and sentences that are modeled by the teacher or by other native speakers.

• When you describe the cost related to an available product, have children repeat the sentences.

• Model each sentence before having children repeat it.

Auditory/VerbalWhole class

Unlock the Problem Read the problem together. Discuss with students the definition of resources as things that are made to sell or use. In this example, the character toy sets are resources. Ask students for examples of other resources (food products, clothing, gas). Help students understand that the problem involves character toys that come in sets of different colors. Be sure students know what each row in the table represents.

• How do you compare the numbers of toy sets made? Possible answer: compare the numbers in the second row of the table using place value; compare ten thousands, then thousands, then hundreds, tens, and ones.

• What is the same about the most of the numbers? Answers will vary. Possible answer: most of the numbers are greater than or equal to 50,000.

• Which toy set is different? How is it different? the red set; possible explanation: only a small number of red sets, 500, were made.

• What is the same about the toy sets for which 50,000 or more were made? Possible answer: their prices are all about $30.

• How is the red toy set different? Possible answer: its price is much greater than the other sets’ prices.

Help students generalize that when more of a product is available (resources are plentiful), it can be sold for a lower price. When less of a product is available (resources are scarce), the price will increase. Explain that this applies not only to toys, but to other products as well, such as food and gas for cars.

Math Talk Use Math Talk to focus on students’ understanding of how product availability is related to the price of an item. Students should apply and extend the concept. If a smaller number of toy sets are made, the product will be even more scarce and the price will be greater.

Mathematical Processes

Leveled Activities ELPS

Beginning: Activity 20 1.A.1, 3.G.2, 4.C.3

Intermediate: Activity 40 4.F.6, 4.G.2, 4.G.4

Advanced: Activity 57 2.C.4, 3.D.2, 3.E

Advanced High: Activity 43 4.F.8, 4.G.2, 4.G.4

thinkcentral.com for the ELL Activity Guide containing these leveled activities.

When there is a lot of product, the cost decreases.When there is less of a product, the cost increases.

667 Module 20

Share and ShowShare and Show

Mathematical ProcessesMath Talk

Anton’s Baseball Cards

Baseball Cards Price

Card A $22

Card B $39

Card C $135

Card D $3

Card E $5

StoreNumber of

Dolls

Tammi’s Dolls 1

Place of Dolls 10

Toy Village 120

Midland Toys 20

Doll Town 10

Anton collects baseball cards. He wants to buy a card

that is very hard to find. Use the table for 1–2.

1. Order the baseball card prices from greatest to least.

2. Which card do you think is the one Anton wants to buy?

Explain using the term resources.

Mrs. Garcia is looking for a doll for her daughter Maria.

The table shows how many of the dolls are available at

some stores. Use the table for 3–4.

3. At which store do you think the price will be the lowest?

4. Explain why a store might lower the price when it has

too many of a particular resource?

The members of a service club want to raise money by

selling muffins. The types of muffins are listed in the

table below in order from the most muffins made to the

least muffins made.

5. Use the prices $1, $2, $3, $4, and assign a price to each

muffin. Explain.

Flavor Chocolate Banana Bran Plain

Price

How could the popularity of an item affect the

number of items made and the price of the

item? Explain.

Possible answer: I assigned prices from least to greatest.

I started with $1 for chocolate because it was the most

available.

Answers will vary. Possible answer: More of a popular item could be made. Its availability could mean a lower price, but a seller could decide to sell it at a higher price to earn more money.

$135, $39, $22, $5, $3

Toy Village

Card C; Possible explanation: when resources are scarce, or

Possible explanation: the store wants people to buy the item,

not very available, their price will be greater. Card C has the

greatest price.

so it might lower the price to attract more people.

Answers may vary.

668

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Enrich

Go to Go to thinkcentral.com for additional enrichmentactivities in the Enrich Activity Guide.

• Explain that Eduardo makes necklaces. Show the descriptions of the different types of necklaces.

A: complicated design, inexpensive beads

B: complicated design, expensive beads

C: simple design, inexpensive beads

D: simple design, expensive beads

• Have pairs of students decide how much money Eduardo should charge for each type of necklace.

• Ask students to share their thoughts with the class. Elicit that Eduardo should charge more when he uses expensive beads, and also when he makes a complicated design.

Logical/MathematicalPartners

Share and ShowThe first problem connects to the learning model. Have students use the MathBoard to explain their thinking.

Have students share their explanations about how they assigned prices to the types of muffins in Exercise 5. It is reasonable for a student to assign a greater price to an available muffin, such as chocolate, because the flavor is more available. Students should be able to explan their reasoning.

Use the checked exercises for Quick Check. Students should show their answers for the Quick Check on the MathBoard.

1

2

3

a student misses the checked exercises

Quick Check

IF

THENDifferentiate Instruction withRtI Tier 1 Lesson 5

Math Talk Use Math Talk to reinforce students’ understanding of how product popularity, as well as its availability, can affect cost.

Mathematical Processes

COMMON ERRORSError Students may forget a zero when ordering numbers.

Example When ordering resources from greatest to least:

75,000; 7,50; 750; 75 instead of

75,000; 7,500; 750; 75

Springboard to Learning Remind students that each group of three digits is separated by a comma in a greater number. Have them check that there are 3 digits to the right of the comma.

CE

Lesson 20.2 668

Problem SolvingProblem Solving

Write MathWrite Math

Show Your Work

Name

For 6–7, use the table.

6. Write MathWrite Math Baseball cards of a famous player are sold

at auctions. At an auction, people call out bids. A bid is

the price they would pay for an item. In which year do

you think the fewest cards for that baseball player were

available? Explain.

7. Multi-Step How much greater was the price

for the 1951 card than prices for the 1952, 1953, and 1954

cards combined?

Leah will sell her headbands at a yard sale. She has

14 blue, 4 black, and 19 red headbands.

8. How should Leah price her headbands if she

prices them based on availability of resources? Assign a

price to each color. Then justify your answer.

9. Multi-Step How much money will Leah earn if she sells

all of her headbands at your prices?

Year Card was Made

Auction Price

1951 $4,810

1952 $1,550

1953 $999

1954 $1,2101951; possible explanation: the card from 1951 sold at the

greatest price, so there were probably fewer cards made or

fewer available to buy.

Answers will vary. Possible answers: black = $3, blue = $2,

and red = $1 because people might pay more money for the

black headbands since there are fewer black headbands

available than blue and red headbands.

$1,051

Answers will vary.

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Module 20 • Lesson 2 669

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LESSON 5 3.2.D

You compare two numbers to decide whether one number is greater than (> ), is less than (< ), or is equal to (= ) the other number.

Use a place-value chart to compare 54,237 and 54,537.

Step 1 The ten thousands digits are the same. The thousands digits are the same.

Step 2 Compare hundreds.

2 hundreds are less than 5 hundreds.

So, 54,237 < 54,537.

You can order three numbers by deciding which number is the greatest or least. Then compare the remaining two numbers.

Order 237, 451, and 405 from least to greatest. 237, 405, 451

Compare the numbers. Write < , > , or = in the .

1. 378 387 2. 3,275 3,257

3. 2,078 989 4. 64,367 67,251

Write the numbers in order from greatest to least.

5. 421, 197, 724

, ,

6. 1,946; 5,632; 8,105

, ,

7. 246, 190, 249

, ,

8. 94,531; 94,852; 94,850

, ,

Compare and Order Whole NumbersOBJECTIVE Use place value to compare multi-digit numbers.

Ten Thousands

Thousands Hundreds Tens Ones

54,237 5 4, 2 3 7

54,537 5 4, 5 3 7

54, 2 37

54, 5 372 < 5

>

>

<

<

8,105

94,852249

724 5,632

94,850246

421 1,946

94,531190

197

Number and Operations 9 Enrich© Houghton Mifflin Harcourt Publishing Company

E95

Name Enrich 95

Saving with Place Value

Carl, Sonny, and Chita saved different amounts of money

each month. Carl saved $1 each month. Sonny saved $10

each month. Chita saved $100 each month. Complete the

table.

Total Saved

Months 1 2 3 4 5 6 7 8 9 10

Carl$1per

month$ $ $ $ $ $ $ $ $ $

Sonny$10per

month$ $ $ $ $ $ $ $ $ $

Chita$100per

month$ $ $ $ $ $ $ $ $ $

Use the table for 1–4.

1. How many months will it take Carl to save $5?

2. When Sonny has saved $120, how much money will Chita have saved?

3. What is the total amount of money saved by all three people in 10 months? Explain how you know.

4. How could you use bills to model the total amount

of money saved by all three people in 10 months? Use only $1 bills, $10 bills, and $100 bills. Show two different ways.

5 months $1,200

$1,110 ; 1,000 1 100 1 10 is 1,110.

1 2 3 4 5 6 7 8 9 10

10 20 30 40 50 70 80 90 100

100 200 300 400 500 600 700 800 9001,000

Possible answer: eleven $100 bills and one $10 bill;

ten $100 bills and eleven $10 bills

60

1

2

3

Enrich 95RtI Tier 1 Lesson 5

Problem SolvingProblems

Problem 7 is a multi-step problem. Students must use addition and subtraction involving the data in the table in order to solve the problem.

For Problem 8, students create their own pricing scheme for the products that are being sold. Then they must justify their answers. Students’ answers should focus on the relationship between the availability of the product or resource and the cost of the product or resource.

Go DeeperHave students do research online to find real-life examples of products whose cost was high because of the limited availability of the products.

Math on the Spot Video Tutor

Through the Math on the Spot Video Tutor, students will be guided through an interactive solving of this type of H.O.T. problem. Use this video to also help students solve the H.O.T. problem in the Interactive Student Edition. With these videos and the H.O.T. problems, students will build skills needed in the TEXAS assessment.

MV

Math on the Spot videos are in theInteractive Student Edition and atthinkcentral.com.

669 Module 20

Daily Assessment TaskDaily Assessment Task

Mathematical Processes

TEXAS Test Prep 13. Analyze Alana paid $15 for a rare stuffed animal. Then the

toymaker announced that thousands more of that animal will

be in stores next week. If Alana sells her stuffed animal online

next week, which best describes what might happen?

A It will sell for more than $15 because there are more resources available.

B It will sell for $20 because it is a scarce resource.

C It will sell for $15 because it is a scarce resource.

D It will sell for less than $15 because there are more resources available.

Fill in the bubble for the correct answer choice.

Use the Robot Toys table for 10–12.

10. A company makes toys that you can build into robots.

The table shows how many of each robot design were

made. Which shows the available resources, from

most to least available?

A 49,000; 800; 9,000; 98,000

B 98,000; 9,000; 800; 49,000

C 49,000; 98,000; 9,000; 800

D 98,000; 49,000; 9,000; 800

11. Apply Which of the robots will sell for the greatest price?

A plane C ship

B train D car

12. Multi-Step If the toy company makes 1,000 more train

robots, how many more ship robots will be available than

train robots?

A 7,200 C 9,200

B 8,200 D 9,800

Robot ToysType of Robot

Number Made

Car 49,000

Plane 98,000

Train 800

Ship 9,000

670

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Daily Assessment Task 1

2

3

Games

Differentiated Centers Kit

• Soar to Success MathWarm-Up 7.32, 7.33

• Enrich 95

• Homework and Practice Lesson 20.2

Can students describe how the availability of resources affects their cost?

Go Deeper After students have completed the daily assessment task, have the class discuss their reasons for their answers. Encourage them to explain using the terms availability of resources or scarcity of resources.

• In Exercise 11, why do you think the train robots might have the greatest price? Possible answer: the train robots are a scarce resource, so their cost will be greater.

• In Exercise 12, how would the availability of 1,000 more train robots affect the price of the train robots? Possible answer: There would be a few more resources available, but the price would probably not go down much because the train robots would still be a scarce resource compared to the other robots.

TEXAS Test Prep CoachTest Prep Coach helps teachers to identify common errors that students can make.

In the Test Prep exercise, if students selected:

A, B or C They did not understand the relationship between product availability and cost.

Essential Question? WriteMathWriteMath

How does the availability of resources affect their cost? Possible answer: when there is very little of a product available or resources are scarce, the cost to buy the product will increase; when there is a lot of a product available or resources are plentiful, the cost will decrease.

LiteratureSoccer BashStudents read the book and use place value to determine if there’s enough money for the soccer team’s party.

GamesMoney ManiaStudents practice comparing money amounts.

Lesson 20.2 670

TEXAS Test PrepLesson CheckLesson Check

Fill in the bubble completely to show your answer.

Use the Collectible Plates table for 7–9.

7. A company makes collectible nature

plates. The table at the right shows

how many plates of each type were

made. Which of the plates will sell

for the greatest price?

A Garden C Mountains

B Seaside D Forest

8. Which shows the number of plates

made in order from least to greatest?

A 2,200; 8,400; 12,800; 17,500

B 8,400; 12,800; 17,500; 2,200

C 17,500; 12,800; 8,400; 2,200

D 12,800; 8,400; 2,200; 17,500

9. Multi-Step The company makes

another 2,000 Seaside plates.

How many more Garden plates will

there be than Seaside plates?

A 4,700 C 14,800

B 19,700 D 2,700

Use the Action Figures table for 10–12.

10. The table shows the price of some

collectible action figures. Based on

their prices, which action figure is

the most available resource?

A Superhero C Gigantor

B Titan D Colossus

11. The action figure company announces

that the Colossus action figure will no

longer be made. In one year, which

action figure will likely cost the most?

A Superhero C Gigantor

B Titan D Colossus

12. Multi-Step Zach buys 1 Titan and

2 Superhero action figures. He

pays with two $20 bills. How much

change does he receive?

A $28 C $40

B $12 D $8

Collectible PlatesType of Plate Number Made

Garden 17,500

Mountains 8,400

Seaside 12,800

Forest 2,200

Action FiguresFigure Price

Superhero $8

Titan $12

Gigantor $27

Colossus $18

672

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Problem SolvingProblem Solving

Homeworkand Practice

Name

Edgar collects model cars. He wants to buy a car

that is very hard to find. Use the table for 1–3.

1. Write the names of the model cars in

order from the greatest price to the

least price.

2. Which car do you think Edgar wants

to buy? Explain.

3. Which model car do you think will be

the easiest for Edgar to find? Explain.

Use the table at the right for 4–6.

4. Lucia collects models of famous

ships. Write the names of the model

ships in order from least number

made to greatest number made.

6. Which model ship will have the most

expensive price? Explain.

5. Which model ship do you think will

be easiest for Lucia to find? Explain.

20.2 Cost of Resources

Personal Financial Literacy—3.9.B Also 3.2.DMATHEMATICAL PROCESSES 3.1.A, 3.1.F

Model CarsCar Price

Rolls Royce $23

Convertible $12

Model T $35

Pick-up Truck $9

4-Door Sedan $5

Models of Famous ShipsShip Number Made

Lusitania 21,000

Bismarck 5,000

Andria Doria 28,000

Titanic 48,000

HMS Victory 15,000

Model T, Rolls Royce, Convertible,

Pick-up Truck, 4-Door Sedan

Model T; Possible explanation: it has the

greatest price, so it is probably the scarce

or hard to fi nd resource that Edgar wants.

4-Door Sedan; Possible explanation: this

model car has the lowest price, so there

are probably a lot of them for sale.

Bismarck, HMS Victory, Lusitania, Andria

Doria, Titanic

Titanic; Possible explanation: there are

more Titanics than any of the other ships.

Possible explanation: there are fewer

Bismarks than other ships, so it is scarce

and will probably have a greater price.

Bismarck;

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Module 20 • Lesson 2 671

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Homework and PracticeUse the Homework and Practice pages to provide students with more practice on the concepts and skills of this lesson.

671-672 Module 20