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eToolkit ePresentations Algorithms Practice EM Facts Workshop Game™ Family Letters Curriculum Focal Points www.everydaymathonline.com Interactive Teacher’s Lesson Guide Assessment Management Common Core State Standards Lesson 7 2 547 Advance Preparation For Part 1, copy the place-value chart from the top of journal page 212 on the board. If possible, use semipermanent chalk, or make a transparency of Math Masters, page 433. Make copies of it available to students. It will also be used in Lesson 7-3. For Part 3, extend the display to include negative powers of 10. For the Math Message, draw 3 name-collection boxes on the board and label 100, 1,000, and 1,000,000. For a mathematics and literacy connection, obtain a copy of Can You Count to a Googol? by Robert E. Wells. Teacher’s Reference Manual, Grades 4–6 pp. 94–98 Key Concepts and Skills • Explore place value using powers of 10. [Number and Numeration Goal 1] • Write and translate numbers in and between standard and exponential notation. [Number and Numeration Goal 4] • Compare exponential notation and standard notation for positive powers of 10. [Number and Numeration Goal 4] • Describe the number patterns inherent to powers of ten.  [Patterns, Functions, and Algebra Goal 1] Key Activities Students use standard notation, number-and-word notation, and exponential notation to represent large numbers. Ongoing Assessment: Recognizing Student Achievement Use the Math Message. [Number and Numeration Goal 4] Ongoing Assessment: Informing Instruction See page 549. Key Vocabulary number-and-word notation powers of 10 Materials Math Journal 2, p. 212 Student Reference Book, p. 5 Study Link 7 1 Math Masters, p. 433 transparency of Math Masters, p. 433 slate Playing First to 100 Student Reference Book, p. 308 Math Masters, pp. 456–458 per partnership: 2 six-sided dice, calculator Students practice solving open number sentences. Math Boxes 7 2 Math Journal 2, p. 213 Geometry Template Students practice and maintain skills through Math Box problems. Study Link 7 2 Math Masters, p. 191 Students practice and maintain skills through Study Link activities. READINESS Finding Patterns in Powers of 10 Math Masters, p. 192 Students complete a powers-of-10 table and describe patterns they see in the table. ENRICHMENT Introducing Negative Exponents and Powers of 0.1 Student Reference Book, p. 7 Math Masters, p. 193 Students explore patterns and notation of negative exponents. EXTRA PRACTICE Multiplying Decimals by Powers of 10 Students solve problems involving the multiplication of decimals by powers of 10. Teaching the Lesson Ongoing Learning & Practice 1 3 2 4 Differentiation Options Exponential Notation for Powers of 10 Objective To introduce number-and-word notation for large numbers and exponential notation for powers of 10.
Transcript
Page 1: Exponential Notation for Powers of 10emccss.everydaymathonline.com/em-crosswalk/pdf/5/g5_tlg_Lesson_7_2_mm_page_192.pdfExplain that number-and-word notation is often used to express

eToolkitePresentations Algorithms Practice

EM FactsWorkshop Game™

Family Letters

CurriculumFocal Points

www.everydaymathonline.com

Interactive Teacher’s

Lesson Guide

AssessmentManagement

Common Core State Standards

Lesson 7�2 547

Advance PreparationFor Part 1, copy the place-value chart from the top of journal page 212 on the board. If possible, use

semipermanent chalk, or make a transparency of Math Masters, page 433. Make copies of it available to

students. It will also be used in Lesson 7-3. For Part 3, extend the display to include negative powers of 10.

For the Math Message, draw 3 name-collection boxes on the board and label 100, 1,000, and 1,000,000. For

a mathematics and literacy connection, obtain a copy of Can You Count to a Googol? by Robert E. Wells.

Teacher’s Reference Manual, Grades 4–6 pp. 94–98

Key Concepts and Skills• Explore place value using powers of 10. 

[Number and Numeration Goal 1]

• Write and translate numbers in and

between standard and exponential notation. 

[Number and Numeration Goal 4]

• Compare exponential notation and standard

notation for positive powers of 10. 

[Number and Numeration Goal 4]

• Describe the number patterns inherent to

powers of ten.  

[Patterns, Functions, and Algebra Goal 1]

Key ActivitiesStudents use standard notation,

number-and-word notation, and exponential

notation to represent large numbers.

Ongoing Assessment: Recognizing Student Achievement Use the Math Message. [Number and Numeration Goal 4]

Ongoing Assessment: Informing Instruction See page 549.

Key Vocabularynumber-and-word notation � powers of 10

MaterialsMath Journal 2, p. 212

Student Reference Book, p. 5

Study Link 7 � 1

Math Masters, p. 433

transparency of Math Masters, p. 433 � slate

Playing First to 100Student Reference Book, p. 308

Math Masters, pp. 456–458

per partnership: 2 six-sided dice,

calculator

Students practice solving open

number sentences.

Math Boxes 7�2Math Journal 2, p. 213

Geometry Template

Students practice and maintain skills

through Math Box problems.

Study Link 7�2Math Masters, p. 191

Students practice and maintain skills

through Study Link activities.

READINESS

Finding Patterns in Powers of 10Math Masters, p. 192

Students complete a powers-of-10 table and

describe patterns they see in the table.

ENRICHMENTIntroducing Negative Exponents and Powers of 0.1Student Reference Book, p. 7

Math Masters, p. 193

Students explore patterns and notation

of negative exponents.

EXTRA PRACTICE

Multiplying Decimals by Powers of 10Students solve problems involving the

multiplication of decimals by powers of 10.

Teaching the Lesson Ongoing Learning & Practice

132

4

Differentiation Options

Exponential Notationfor Powers of 10

Objective To introduce number-and-word notation for large

numbers and exponential notation for powers of 10.

��������

547_EMCS_T_TLG2_G5_U07_L02_576914.indd 547547_EMCS_T_TLG2_G5_U07_L02_576914.indd 547 3/1/11 11:54 AM3/1/11 11:54 AM

Page 2: Exponential Notation for Powers of 10emccss.everydaymathonline.com/em-crosswalk/pdf/5/g5_tlg_Lesson_7_2_mm_page_192.pdfExplain that number-and-word notation is often used to express

548 Unit 7 Exponents and Negative Numbers

Getting Started

Ongoing Assessment: Math Message �

Recognizing Student Achievement

Use the Math Message to assess students’ familiarity with writing exponential

notation for powers of 10 and their ability to write equivalent names for numbers.

[Number and Numeration Goal 4]

1 Teaching the Lesson

▶ Math Message Follow-Up WHOLE-CLASSDISCUSSION

Have students share their answers. Write the different names in name-collection boxes on the board. Answers should include the following:

� 100: 10 ∗ 10; 1,000 _ 10 ; 1 hundred; 102

� 1,000: 10 ∗ 10 ∗ 10; 10,000 _ 10 ; 1 thousand; 103

� 1,000,000: 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10; 5,000,000 _ 5 ; 1 million; 106

Ask students to describe the kinds of notation that are included on the board. Examples of powers of 10 written in exponential notation are 102 , 103 , and 106 . Examples of powers of 10 written in number-and-word notation are 1 hundred, 1 thousand, and 1 million.

Explain that number-and-word notation is often used to express large numbers using a few numerals and one or two words (for example, 25 billion, 5 hundred thousand), because long strings of zeros can be hard to read. Write number-and-word notation along with the example 25 billion on the board or transparency. Write standard notation along with the example 25,000,000,000. Ask students to compare the two ways of expressing the same number.

Discuss how to translate from number-and-word notation to standard notation.

� One way: 25 billion = 25 ∗ 1,000,000,000 = 25,000,000,000

Math Message �On a half-sheet of paper, make name-collection boxes for 100; 1,000; and 1,000,000. Write three different names in each box. Use exponential notation at least once.

Study Link 7�1 Follow-UpHave partners share answers and resolve any differences.

Mental Math and Reflexes Use slates. Dictate numbers and have students identify digits in given places.

63 0,726. Circle the 10-thousands digit. Underline the hundred-thousands digit.

26 3,014,613. Circle the 10-millions digit. Underline the ten-thousands digit.

4 3,269,432.89. Circle the 10-millions digit. Underline the tenths digit.

548-551_EMCS_T_TLG2_G5_U07_L02_576914.indd 548548-551_EMCS_T_TLG2_G5_U07_L02_576914.indd 548 3/1/11 11:59 AM3/1/11 11:59 AM

Page 3: Exponential Notation for Powers of 10emccss.everydaymathonline.com/em-crosswalk/pdf/5/g5_tlg_Lesson_7_2_mm_page_192.pdfExplain that number-and-word notation is often used to express

Date Time

Study the place-value chart below.

In our place-value system, the powers of 10 are grouped into sets of three: ones,

thousands, millions, billions, and so on. These groupings, or periods, are helpful

for working with large numbers. When we write large

numbers in standard notation, we separate these groups

of three with commas.

There are prefixes for the periods and for other important

powers of 10. You know some of these prefixes from your

work with the metric system. For example, the prefix kilo- in

kilometer identifies a kilometer as 1,000 meters.

Use the place-value chart for large numbers and the

prefixes chart to complete the following statements.

Example:

1 kilogram equals 10 , or one , grams.

1. The distance from Chicago to New Orleans is about 103, or one , miles.

2. A millionaire has at least 10 dollars.

3. A computer with 1 gigabyte of RAM memory can hold approximately 10 , or

one , bytes of information.

4. A computer with a 1 terabyte hard drive can store approximately 10 , or

one , bytes of information.

5. According to some scientists, the hearts of most mammals will beat about 109, or

one , times in a lifetime.

Prefixes

tera- trillion (1012)

giga- billion (109)

mega- million (106)

kilo- thousand (103)

hecto- hundred (102)

deca- ten (101)

uni- one (100)

deci- tenth (10–1)

centi- hundredth (10–2)

milli- thousandth (10–3)

micro- millionth (10–6)

nano- billionth (10–9)

Periods

Millions Thousands Ones

Hundred Ten Hundred Ten Billions millions millions Millions thousands thousands Thousands Hundreds Tens Ones

109 108 107 106 105 104 103 102 101 100

thousand3

Guides for Powers of 10LESSON

7�2

thousand

trillion

billion

billion

12

9

6

209-247_EMCS_S_MJ2_U07_576434.indd 212 1/25/11 1:09 PM

Math Journal 2, p. 212

Student Page

Lesson 7�2 549

� Another way: Use a place-value chart to position the leading digits. Then add zeros to complete the number.

Have volunteers write number-and-word notations for the class to write in standard notation.

▶ Introducing Exponential WHOLE-CLASSDISCUSSION

Notation for Powers of 10(Student Reference Book, p. 5)

Refer students to page 5 of the Student Reference Book. As a class, discuss the presented definition of powers of 10 — whole numbers that can be written using only 10s as factors. For example, 1,000 = 10 ∗ 10 ∗ 10 = 103.

Ask students to look at the Powers of 10 Chart on the page and share their ideas about what patterns might help them figure out standard notation for powers of 10. Guide them to observe that the number of zeros in a power of 10, written in standard notation, is equal to the exponent of that number, written in exponential notation. For example, 1,000,000 has 6 zeros, so the exponent of the power of 10 is 6; 1,000,000 = 106.

The next three periods to the left of billions are trillions, then quadrillions, then quintillions.

● How many zeros are needed to write 1 trillion in standard notation? 12 zeros

● How many times will 10 appear in the repeated factor expression? 12 times

● How many periods are to the right of trillions? 4 periods

● What is the relationship between the number of periods to the right of trillions and the exponent when 1 trillion is written in exponential notation? Each period has 3 digits, so 1 trillion would have 3 digits ∗ 4 periods, or 12 zeros.

Record a few examples on the board, and ask students to write these numbers in exponential or standard notation. Suggestions:

� 10,000 104; 100,000 105; 10 101; 10,000,000 107

� 103 1,000; 102 100; 105 100,000; 1010 10,000,000,000

▶ Using Guides for Powers of 10 PARTNER ACTIVITY

(Math Journal 2, p. 212; Student Reference Book, p. 5;

Math Masters, p. 433)

Have students read the introductory paragraphs on journal page 212. Use the example to discuss how to use the place-value chart and the table of prefixes to work with powers of 10. Mention that these guides are also found on the inside front cover of their journals. Assign the problems on the rest of the page.

Ongoing Assessment: Informing Instruction

Watch for students who have difficulty

identifying the exponents for Problems 3

and 4. Suggest that they use the place-

value chart on the journal page to first write

the number in standard notation and then

count the 0s to determine the exponent.

Alternatively, use a transparency of Math

Masters, page 433 and have students use

copies of the page to practice writing in

standard notation.

548-551_EMCS_T_TLG2_G5_U07_L02_576914.indd 549548-551_EMCS_T_TLG2_G5_U07_L02_576914.indd 549 3/1/11 11:59 AM3/1/11 11:59 AM

Page 4: Exponential Notation for Powers of 10emccss.everydaymathonline.com/em-crosswalk/pdf/5/g5_tlg_Lesson_7_2_mm_page_192.pdfExplain that number-and-word notation is often used to express

Date Time

213

3. Measure ∠P to the nearest degree.

P

∠P measures about 19° .

4. Calculate the sale price.

1. Measure the length and width of each of the following objects to the nearest half inch.

Answers vary. a. piece of paper b. dictionary

length in. width in. length in. width in.

c. palm of your hand d. (your choice)

length in. width in. length in. width in.

2. Amanda collects dobsonflies. Below are the lengths, in millimeters, for the flies in her collection.

95, 107, 119, 103, 102, 91, 115, 120, 111, 114, 115, 107, 110, 98, 112

a. Circle the stem-and-leaf plot below that represents this data.

Stems Leaves (100s and 10s) (1s)

9 1 5 8

10 2 3 7 7

11 0 1 2 4 5 5 9

12 0

Stems Leaves (100s and 10s) (1s)

9 1 5 8

10 2 3 7

11 0 1 2 4 5 9

12 0

Stems Leaves (100s and 10s) (1s)

9 1 5 8 8 8

10 2 3 7 7 7

11 0 1 2 4 5 5 5

12 0

b. Find the following landmarks for the data.

Median: 110 Minimum: 91 Range: 29 Mode(s): 107, 115

Regular Discount Sale Price Price

$12.00 25%

$7.99 25%

$80.00 40%

$19.99 25%

$9.00

$5.99

$48.00

$14.99

183

117–119

51204

Math BoxesLESSON

7�2

EM3cuG5MJ2_U07_209-247.indd 213 1/19/11 7:42 AM

Math Journal 2, p. 213

Student Page

STUDY LINK

7�2 Guides for Powers of 10

4–6376

Name Date Time

There are prefixes that name powers of 10. You know some of them from the

metric system. For example, kilo- in kilometer (1,000 meters). It’s helpful to

memorize the prefixes for every third power of 10 through one trillion.

Memorize the table below. Have a friend quiz you. Then cover the table, and try

to complete the statements below.

1. More than 10 9 , or one billion , people live in China.

2. One thousand, or 103

, feet is a little less than 1

_ 5 of a mile.

3. Astronomers estimate that there are more than 10 12 , or one trillion ,

stars in the universe.

4. More than one million, or 106

, copies of The New York Times are sold every day.

5. A kiloton equals one thousand , or 103

, metric tons.

6. A megaton equals one million , or 106

, metric tons.

Standard Number-and-Word Exponential Prefix

Notation Notation Notation

1,000 1 thousand 103 kilo-

1,000,000 1 million 106 mega-

1,000,000,000 1 billion 109 giga-

1,000,000,000,000 1 trillion 1012 tera-

Practice

Find the prime factorization of each number, and write it using exponents.

7. 48 = 24 ∗ 3 8. 60 = 22 ∗ 3 ∗ 5

Write each number in expanded notation.

9. 3,264 = 3,000 + 200 + 60 + 4

10. 675,511 = 600,000 + 70,000 + 5,000 + 500 + 10 + 1

EM3MM_G5_U07_187-220.indd 191 1/19/11 11:41 AM

Math Masters, p. 191

Study Link Master

550 Unit 7 Exponents and Negative Numbers

2 Ongoing Learning & Practice

▶ Playing First to 100 PARTNER ACTIVITY

(Student Reference Book, p. 308; Math Masters,

pp. 456–458)

Algebraic Thinking Students practice solving open number sentences by playing First to 100. This game was introduced in Lesson 4-7. For detailed instructions, see Student Reference Book, page 308.

▶ Math Boxes 7�2

INDEPENDENT ACTIVITY

(Math Journal 2, p. 213)

Mixed Practice Math Boxes in this lesson are paired with Math Boxes in Lessons 7-4 and 7-6. The skill in Problem 4 previews Unit 8 content.

▶ Study Link 7�2

INDEPENDENT ACTIVITY

(Math Masters, p. 191)

Home Connection Students are asked to memorize the Guides for Powers of 10 and answer questions about them.

3 Differentiation Options

READINESS PARTNER ACTIVITY

▶ Finding Patterns in 15–30 Min

Powers of 10(Math Masters, p. 192)

To investigate patterns in powers of 10, have students complete the table on the Math Masters page and describe the patterns they identify in the table.

ENRICHMENT PARTNER ACTIVITY

▶ Introducing Negative Exponents 15–30 Min

and Powers of 0.1(Student Reference Book, p. 7; Math Masters, p. 193)

To apply students’ understanding of exponents, have them explore the patterns and notation of negative exponents. Read and discuss Student Reference Book,

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EM3cuG5TLG2_548-551_U07L02.indd 550EM3cuG5TLG2_548-551_U07L02.indd 550 1/25/11 2:52 PM1/25/11 2:52 PM

Page 5: Exponential Notation for Powers of 10emccss.everydaymathonline.com/em-crosswalk/pdf/5/g5_tlg_Lesson_7_2_mm_page_192.pdfExplain that number-and-word notation is often used to express

LESSON

7�2

Name Date Time

Powers of 10

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187-220_EMCS_B_MM_G5_U07_576973.indd 192 3/16/11 2:50 PM

Math Masters, p. 192

Teaching Master

py

gg

p

Negative powers of 10 can be used to name decimal places.

Example: 10 -2 = 1

_ 102 =

1

_ 10 ∗ 10

= 1

_ 10

∗ 1

_ 10

= 0.1 ∗ 0.1 = 0.01

Very small decimals can be hard to read in standard notation, so people often use

number-and-word notation, exponential notation, or prefixes instead.

LESSON

7�2

Name Date Time

Negative Powers of 10

Our base-ten place-value system works for decimals as well as for whole numbers.

Tens Ones . Tenths Hundredths Thousandths

10s 1s . 0.1s 0.01s 0.001s

Use the table above to complete the following statements.

1. A fly can beat its wings once every 10 -3 seconds, or once every one thousandth

of a second. This is one second.

2. Earth travels around the sun at a speed of about one inch per microsecond.

This is 10-6

second, or a of a second.

3. Electricity can travel one foot in a nanosecond, or one of a second.

This is 10-9

second.

4. In 10 second, or one picosecond, an air molecule can spin once.

This is one of a second.

Guides for Small Numbers

Number-and-Word Exponential Notation

Standard Prefix Notation Notation

1 tenth 10 -1 = 1

_ 10

0.1 deci-

1 hundredth 10 -2 = 1

_ 10 ∗ 10

0.01 centi-

1 thousandth 10 -3 = 1

_ 10 ∗ 10 ∗ 10

0.001 milli-

1 millionth 10 -6 = 1 __

10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 0.000001 micro-

1 billionth 10 -9 = 1 ___

10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 0.000000001 nano-

1 trillionth 10 -12 = 1

____ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10

0.000000000001 pico-

milli

millionth

billionth

trillionth

-12

187-220_EMCS_B_MM_G5_U07_576973.indd 193 3/21/11 12:59 PM

Math Masters, p. 193

Teaching Master

Links to the Future

Lesson 7�2 551

page 7. Emphasize that negative exponents are another way to represent numbers that are less than 1.

Use examples to discuss converting between exponential notation with negative exponents and fractions.

Suggestions:

5-2 = 1 _ 52 = 1 _ 5 ∗ 5 = 1 _ 25

4-3 = 1 _ 43 = 1 _ 4 ∗ 4 ∗ 4 = 1 _ 64

2-4 = 1 _ 24 = 1 _ 2 ∗ 2 ∗ 2 ∗ 2 = 1 _ 16

Negative exponents can be used to express negative powers of 10.

10-3 = 1 _ 103 = 1 _ 10 ∗ 10 ∗ 10 = 1 _ 1,000

This equation also shows that negative powers of 10 are also positive powers of 0.1.

10-3 = 1 _ 10 ∗ 1 _ 10 ∗ 1 _ 10 = 0.1 ∗ 0.1 ∗ 0.1 = 0.13 = 0.001

Discuss the table on Math Masters, page 193. Students work with their partners, using the table to answer the questions that follow. Briefly go over the answers.

Negative exponents and powers of 0.1 will be investigated further in Sixth Grade

Everyday Mathematics. The Enrichment activity is provided for exposure only.

EXTRA PRACTICE WHOLE-CLASSDISCUSSION▶ Multiplying Decimals by

Powers of 10 5–15 Min

To offer students more practice multiplying decimals by powers of 10, pose problems like those below. For each problem, have students write the original problem, rewrite the problem with the power of 10 written in standard notation, and then solve the problem.

● 2.3 ∗ 101 2.3 ∗ 10; 23

● 35.1 ∗ 103 35.1 ∗ 1,000; 35,100

● 40.7 ∗ 104 40.7 ∗ 10,000; 407,000

● 0.52 ∗ 105 0.52 ∗ 100,000; 52,000

Have students explain the relationship between multiplying by a power of 10 and the placement of the decimal point in the product.

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Page 6: Exponential Notation for Powers of 10emccss.everydaymathonline.com/em-crosswalk/pdf/5/g5_tlg_Lesson_7_2_mm_page_192.pdfExplain that number-and-word notation is often used to express

Copyrig

ht ©

Wrig

ht G

roup/M

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raw

-Hill

192

LESSON

7�2

Name Date Time

Powers of 10

Fin

d t

he p

attern

s a

nd c

om

ple

te t

he t

able

belo

w.

Do n

ot

use y

our

Stu

dent

Refe

rence B

ook.

1,0

00,0

00

100,0

00

10,0

00

1

one

hundre

done

10 ∗

10 ∗

10

10 ∗

1

_

10

10

110

0

1.

Describe a

t le

ast

one p

attern

you u

sed t

o c

om

ple

te t

he t

able

.

2.

Describe w

hat

happens t

o t

he d

ecim

al poin

t in

the s

tandard

nota

tion a

s y

ou m

ove o

ne c

olu

mn t

o t

he

right

in t

he t

able

.

3.

Describe w

hat

happens t

o t

he v

alu

e o

f th

e d

igit 1

when y

ou m

ove o

ne c

olu

mn t

o t

he left.

4.

Describe w

hat

happens t

o t

he v

alu

e o

f th

e d

igit 1

wh

en

yo

u m

ove

one c

olu

mn t

o t

he r

ight.

5.

Describe a

pattern

in t

he n

um

ber

of

zero

s u

sed in t

he s

tandard

nota

tion t

hat

you u

sed t

o c

om

ple

te t

he t

able

.

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