Scientific Notation Objective To introduce scientific notation. www.everydaymathonline.com ePresentations eToolkit Algorithms Practice EM Facts Workshop Game™ Teaching the Lesson Family Letters Assessment Management Common Core State Standards Ongoing Learning & Practice Key Concepts and Skills Math Boxes 7 3 • Explore the place value of numbers written as powers of 10. Math Journal 2, p. 218 Students practice and maintain skills through Math Box problems. [Number and Numeration Goal 1] • Translate numbers from scientific notation to standard and number-and-word notation. [Number and Numeration Goal 1] • Use number patterns to solve problems involving exponents. Study Link 7 3 Math Masters, p. 194 Students practice and maintain skills through Study Link activities. [Patterns, Functions, and Algebra Goal 1] Key Activities Students use powers of 10 to write numbers in expanded notation. They solve multiplication expressions containing exponents and translate numbers written in scientific notation into standard and numberand-word notation. Students practice writing and comparing numbers written in scientific notation by playing Scientific Notation Toss. Ongoing Assessment: Recognizing Student Achievement Use journal page 217. [Number and Numeration Goal 1] Key Vocabulary expanded notation scientific notation Materials Math Journal 2, pp. 214–217 Student Reference Book, p. 329 Study Link 72 Class Data Pad slate per partnership: 2 six-sided dice Advance Preparation Teacher’s Reference Manual, Grades 4–6 pp. 94–98 552 Unit 7 Exponents and Negative Numbers Curriculum Focal Points Interactive Teacher’s Lesson Guide Differentiation Options READINESS Using Place Value to Rename Numbers Math Masters, p. 195 Students rename numbers using place value and number-and-word notation. EXTRA PRACTICE Writing Numbers in Expanded Notation Math Masters, p. 196 Students write whole numbers in expanded notation as addition and multiplication expressions. ELL SUPPORT Comparing Notations for Numbers Differentiation Handbook, p. 149 Students compare and contrast the terms standard notation and exponential notation. Mathematical Practices SMP1, SMP2, SMP4, SMP5, SMP6, SMP7, SMP8 Getting Started Content Standards 5.NBT.2 Mental Math and Reflexes Math Message Use your slate procedures for problems such as the following: Complete Problems 1–10 on page 214 in your journal. Reminder: Calculations with exponents are done before other factors are multiplied. 3.4 ∗ 10 = 34 3.4 ∗ 102 = 340 3.4 ∗ 103 = 3,400 2.41 ∗ 10 = 241 2.41 ∗ 103 = 2,410 0.241 ∗ 102 = 24.1 2 54 ∗ 103 = 54,000 5,400 ÷ 103 = 5.4 5,400 ÷ 104 = 0.54 Study Link 7 2 Follow-Up Partners share their solutions. Then have students answer the following questions on their slates: 3 • One thousand equals what power of 10? 10 • Which prefix means thousand? kilo6 • What is another name for 10 ? 1 million • Which prefix means million? mega• What does the prefix tera- mean? trillion 12 • 1 trillion equals what power of 10? 10 1 Teaching the Lesson ▶ Math Message Follow-Up WHOLE-CLASS ACTIVITY (Math Journal 2, p. 214) Ask students to share their solutions for Problems 1–10. Ask a volunteer to write 236 on the Class Data Pad using expanded notation. 236 = 200 + 30 + 6 Show the use of powers of 10 to write numbers in expanded notation. Write 236 = (2 ∗ 102) + (3 ∗ 101) + (6 ∗ 100) on the Class Data Pad. Ask another volunteer to evaluate the expressions in parentheses. 236 = (2 ∗ 10 ∗ 10) + (3 ∗ 10) + (6 ∗ 1) = (2 ∗ 100) + (3 ∗ 10) + (6 ∗ 1) = 200 + 30 + 6 Ask students what observations or connections they notice between the number sentences. Point out that the expanded notation expressions contain powers of 10 written in standard notation, as products of 10s, and in exponential notation. As a class, read the introduction to scientific notation on the journal page. Problems 6–14 are given in scientific notation. Student Page Date Time LESSON 73 Scientific Notation Complete the following pattern. 1. 102 = 10 ∗ 10 = 100 1,000 10 ∗ 10 ∗ 10 ∗ 10 10,000 = ∗ ∗ ∗ ∗ 10 10 10 10 10 100,000 = = 4. 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 ∗ 10 = 1,000,000 5. 10 = 10 2. 103 = 10 ∗ 10 ∗ 10 = 3. 104 = 5 6 Use the answers to Problems 1–5 to help you complete the following. Do Problems 11–14 as a class. Ask volunteers to rename the power of 10 as a product of 10s. Then carry out the multiplication. Example: 5 ∗ 103 = 5 ∗ (10 ∗ 10 ∗ 10) = 5 ∗ 1,000 = 5,000 ▶ Translating Scientific Notation PARTNER ACTIVITY (Math Journal 2, pp. 215 and 216) 6. 2 ∗ 102 = 2 ∗ 100 = 200 7. 3 ∗ 103 = 3 ∗ 8. 4 ∗ 104 = 9. 6 ∗ 105 = 10. 8 ∗ 106 = 1,000 = 3,000 4 10,000 = 40,000 ∗ 6 ∗ 100,000 = 600,000 8 ∗ 1,000,000 = 8,000,000 Scientific notation is a useful way to write very large or very small numbers. A number is in scientific notation when it is written as a product of two factors as follows: One factor is greater than or equal to 1 and less than 10. The other factor is a power of 10. Example: In scientific notation, 4,000 is written as 4 ∗ 103. It is read as four times ten to the third power. Write each of the following in standard notation and number-and-word notation. Standard Notation Science Link Ask a student to select an event from journal page 215 and read, in scientific notation, how many years ago the event took place. Demonstrate how to use the place-value chart on page 216 to write the number in standard notation. 5,000 700 = 20,000 = = 5,000,000 11. 5 ∗ 103 = 12. 7 ∗ 102 13. 2 ∗ 104 14. 5 ∗ 106 Number-and-Word Notation 5 thousand 7 hundred 20 thousand 5 million Math Journal 2, p. 214 209-247_EMCS_S_MJ2_G5_U07_576434.indd 214 8/25/11 8:48 AM Lesson 7 3 553 Student Page Date Example: The first fish appeared about 4 ∗ 108 years ago. To express this number of years in standard notation, find 108 on the place-value chart and write 4 beneath it, followed by the appropriate number of zeros in the cells to the right. From the chart, 4 ∗ 108 can easily be read as four hundred million. Time LESSON History of Earth 73 continued Billion 100 M 10 M Million 100 Th 10 Th Thousand 100 10 One 1 2 109 108 107 106 105 104 103 102 101 5 4 0 0 4 3 2 1 0 0 0 0 5 0 6 0 0 0 0 0 0 5 6 0 0 0 0 0 0 0 0 8 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 4 5 6 7 8 9 10 100 0 0 0 0 0 0 0 0 0 0 Ask partners to complete Problems 1–8 on the chart. Circulate and assist. The scientific notations for Problems 5 and 7 contain decimals. Discuss the meanings of decimals in scientific notation. For example, to convert 6.5 ∗ 107 to standard notation, think of number-and-word notation. The 6 represents 6 ten millions, or 60 million. The 0.5 represents half of 1 ten million, or 5 million. So 6.5 ∗ 107 = 65 million. Write the 6 in the 107 column, the 5 in the 106 column, and complete the row with 0s. This shows that 6.5 ∗ 107 = 65,000,000. Work with a partner to answer the questions. Write your answers in standard notation. 11. According to the estimates by scientists, about how many years passed from the formation of Earth until the first signs of life? About 1,000,000,000 years 12. About how many years passed between the appearance of the first fish and the appearance of forests and swamps? 13. According to the geological record, about how long did dinosaurs roam on Earth? About 100,000,000 years About 185,000,000 years List the following numbers on the Class Data Pad, and ask volunteers to rename the numbers using decimals. 15 hundred 1.5 thousand Math Journal 2, p. 216 209-247_EMCS_S_MJ2_G5_U07_576434.indd 216 8/25/11 8:48 AM 35 thousand 3.5 ten thousand 230 million 2.3 hundred million Ask students to explain how they would write these answers in scientific notation. Thousands is 103, so 1.5 thousand = 1.5 ∗ 103; ten thousands is 104, so 3.5 ten thousand = 3.5 ∗ 104; hundred millions is 108, so 2.3 hundred million = 2.3 ∗ 108. Add students’ responses to the Class Data Pad. Ask partners to complete the journal page. Circulate and assist. ▶ Reviewing Expanded Notation (Math Journal 2, p. 217) Student Page Date Time LESSON 73 Expanded Notation Each digit in a number has a value depending on its place in the numeral. Example: Ask volunteers to identify the value of each digit in 2,784. Ask other volunteers to write the solutions for Problem 1 on the board. Discuss how the number sentences are related. Expect students to reference ideas from the Math Message discussion. Then have students complete the page. 2,784 4 8 7 2 INDEPENDENT ACTIVITY ones or 4 ∗ 1 or 4 tens or 8 ∗ 10 or 80 hundreds or 7 ∗ 100 or 700 thousands or 2 ∗ 1,000 or 2,000 Numbers written in expanded notation are written as addition expressions showing the value of the digits. 1. a. Write 2,784 in expanded notation as an addition expression. 2,784 = 2,000 + 700 + 80 + 4 b. Write 2,784 in expanded notation as the sum of multiplication expressions. c. Write 2,784 in expanded notation as the sum of multiplication expressions using powers of 10. 3 2 1 0 2,784 = (2 ∗ 1,000) + (7 ∗ 100) + (8 ∗ 10) + (4 ∗ 1) 2,784 = (2 ∗ 10 ) + (7 ∗ 10 ) + (8 ∗ 10 ) + (4 ∗ 10 ) 2. Write 987 in expanded notation as an addition expression. 3. Write 8,945 in expanded notation as the sum of multiplication expressions. 4. Write 4,768 in expanded notation as the sum of multiplication expressions using powers of 10. 3 2 1 0 987 = 900 + 80 + 7 8,945 = (8 ∗ 1,000) + (9 ∗ 100) + (4 ∗ 10) + (5 ∗ 1) 4,768 = (4 ∗ 10 ) + (7 ∗ 10 ) + (6 ∗ 10 ) + (8 ∗ 10 ) 5. a. 6,125 = 6,000 + 100 + 20 + 5 b. Write 6,125 in expanded notation as the sum of multiplication expressions. c. Write 6,125 in expanded notation as the sum of multiplication expressions using powers of 10. 3 2 1 0 6,125 = (6 ∗ 1,000) + (1 ∗ 100) + (2 ∗ 10) + (5 ∗ 1) 6,125 = (6 ∗ 10 ) + (1 ∗ 10 ) + (2 ∗ 10 ) + (5 ∗ 10 ) Math Journal 2, p. 217 554 Unit 7 Journal Page 217 Problems 1–5 Use journal page 217, Problems 1–5 to assess students’ understanding of place value and their ability to translate numbers written in standard notation to expanded notation. Students are making adequate progress if they have accurately converted the numbers to expanded notation. Some students may be able to write in expanded notation using powers of 10. [Number and Numeration Goal 1] Write 6,125 in expanded notation as an addition expression. EM3cuG5MJ2_U07_209-247.indd 217 Ongoing Assessment: Recognizing Student Achievement 1/19/11 7:42 AM Exponents and Negative Numbers Student Page ▶ Playing Scientific-Notation Toss PARTNER ACTIVITY Date Time LESSON Math Boxes 73 (Student Reference Book, p. 329) 1. 3 Circle the fractions that are equivalent to _ 8. 9 _ 6 _ Have students read the directions on page 329 in the Student Reference Book. Ask a volunteer to demonstrate how the game is played. 8 _ 24 12 4 _ 3 5 Charlene has 2_ 8 yards of fabric. The 3 curtain she is making requires 3_ 4 yards. How much more fabric does she need? 2. 15 _ 9 40 1_18 yards 66 67 3. 10 5 35 c. _ 40 = 7 ▶ Math Boxes 7 3 42 b. _ 66 d. 8 5 = 1 _ e. 2 4 _ a. 2 Ongoing Learning & Practice 20 f. 4 = 7 9 = _ 21 6 = _ 27 Rule 3 a. b. Mixed Practice Math Boxes in this lesson are paired with Math Boxes in Lesson 7-1. The skills in Problems 2 and 6 preview Unit 8 content. 1 20 5 0 0 231 232 3 Lilia did 2_ 4 hours of homework on 3 Saturday and _ 4 hour of homework on Sunday. What is the total time she spent on homework over the weekend? = 32 (16 2) 3_12 hours = (32 16) 2 (6.5 + 8.3) (3 – 1) = d. (4 ∗ 12) + 8 = 7 4 0.25 9 6. c. 16 2 Solve. 4 1 28 ÷4 7 59 5. Complete the “What’s My Rule?” table, and state the rule. 4. 11 INDEPENDENT ACTIVITY (Math Journal 2, p. 218) 71 Find the missing numerator or denominator. 7.4 56 219 ▶ Study Link 7 3 70 Math Journal 2, p. 218 INDEPENDENT ACTIVITY EM3cuG5MJ2_U07_209-247.indd 218 1/19/11 7:42 AM (Math Masters, p. 194) Home Connection Students practice reading and interpreting numbers written in scientific notation. Then they write the numbers in number-and-word notation. 3 Differentiation Options READINESS ▶ Using Place Value to PARTNER ACTIVITY 15–30 Min Rename Numbers (Math Masters, p. 195) Study Link Master Name Date STUDY LINK 73 Time Interpreting Scientific Notation Scientific notation is a short way to represent large and small numbers. In scientific notation, a number is written as the product of two factors. One factor is a number greater than or equal to 1 and less than 10. The other factor is a power of 10. Scientific notation: 4 ∗ 104 Meaning: To explore the use of place value and number-and-word notation to rename numbers, have partners complete name-collection boxes. Refer students to the place-value chart on Math Masters, page 195. Guides for Powers of 10 Multiply 104 (10,000) by 4. 4 ∗ 104 = 4 ∗ 10,000 = 40,000 Number-and-word notation: 40 thousand Multiply 106 (1,000,000) by 6. 103 one thousand 106 one million 109 one billion 1012 one trillion Scientific notation: 6 ∗ 106 Meaning: 8 6 ∗ 106 = 6 ∗ 1,000,000 = 6,000,000 Number-and-word notation: 6 million Complete the following statements. Pose the following questions: 1 of 10? 1 ● What is _ 10 ● 1 of 100? 10 What is _ ● 1 of 1,000? 100 What is _ ● 10 What is 10 1 _ 10 of 10,000? 1,000 1. The area of Alaska is about 6 ∗ 105, or 600 thousand, square miles. 3 million, square miles. 6 billion, people in the world. It is estimated that about 5 ∗ 10 , or 500 million , people speak English as The area of the lower 48 states is about 3 ∗ 106, or 9 2. There are about 6 ∗ 10 , or 3. 8 their first or second language. 4. In Bengal, India, and Bangladesh there are about 2.6 ∗ 108, or people who speak Bengali. 5. At least 1 person in each of 1 ∗ 107 households, or watches the most popular TV shows. 260 million , 10 million , Source: The World Almanac and Book of Facts, 2000 Practice 6. 5 ∗ (32 + 42) = 8. 2 ∗ (9 + h) = 20 125 h=1 7. 3 ∗ (9 + 16) = 9. g = (7 - 2 ) 2 2 75 g = 45 Math Masters, p. 194 187-220_EMCS_B_MM_G5_U07_576973.indd 194 8/16/11 3:45 PM Lesson 7 3 555 Teaching Master Name Date LESSON Explain that just as we think of the place-value of each column as 10 times that of the column to its right, we can also think of the 1 of the column to its left. place-value of each column as _ 10 Time Using Place Value to Rename Numbers 73 Write the numbers from the name-collection box tag in the place-value chart. Then follow the pattern in Problem 1 to complete each name-collection box. Billions 100 10 Millions 1 100 10 Thousands 1 100 1. 2. 1 1 3. 4. 1. Example: 4 6 10 100 10 1 1 1 0 0 0 0 3 8 0 0 0 0 0 0 0 0 0 0 Sample answers: 2. 1,300 1,800 1,000 + 300 1 thousand 3 hundred 1,000 + 800 1 thousand 8 hundred 18 hundred 800 1_ 1,000 thousands 1.8 thousands 8 1_ 10 thousands 13 hundred 300 1_ 1,000 thousands 3 1_ 10 thousands 1.3 thousands 3. We can use these relationships to rename numbers. In the example on the Math Masters page, we can think how many hundreds in 1,300? and rename it as 13 hundred. If we think how many thousands in 1,300, we can rename it as 1.3 thousand. Since 3 of 1,000. 1 of 1,000, then 300 is _ 100 is _ 10 10 Ones 1 Ask students to first write the numbers from the name-collection box tags in the place-value chart and then follow the pattern in the example to complete the name-collection boxes for these numbers. Have students share their answers. Consider making posters to display the completed name-collection boxes. 4. 1,600,000 1.4 million 1,000,000 + 400,000 14 hundred-thousands 400,000 millions 1_ 1,000,000 400 millions 1_ 1,000 4 millions 1_ 10 16 hundred-thousands 1.6 millions 1,000,000 + 600,000 6 1_ 10 millions py g g p 1,400,000 INDEPENDENT ACTIVITY EXTRA PRACTICE ▶ Writing Numbers in Math Masters, p. 195 187-220_EMCS_B_MM_G5_U07_576973.indd 195 15–30 Min Expanded Notation 9/27/11 3:50 PM (Math Masters, p. 196) Students practice writing whole numbers in expanded notation as addition expressions and multiplication expressions. Adjusting the Activity Have students write expanded notation as multiplication expressions for decimals. Suggestions: 9.56, 87.125, 392.394 A U D I T O R Y Teaching Master Name Date LESSON 73 Standard Notation: 325 B Expanded Notation as an addition expression: 300 + 20 + 5 C Expanded Notation as the sum of multiplication expressions: (3 ∗ 100) + (2 ∗ 10) + (5 ∗ 1) D Expanded Notation as the sum of multiplication expressions using powers of 10: (3 ∗ 102) + (2 ∗ 101) + (5 ∗ 100) ▶ Comparing Notations b. c. d. 2. a. 2,756 c. (2 ∗ 1,000) + (7 ∗ 100) + (5 ∗ 10) + (6 ∗ 1) d. (2 ∗ 103) + (7 ∗ 102) + (5 ∗ 101) + (6 ∗ 100) 3. a. 983 b. 900 + 80 + 3 c. (9 ∗ 100) + (8 ∗ 10) + (3 ∗ 1) d. (9 ∗ 102) + (8 ∗ 101) + (3 ∗ 100) 4. a. 7,452 b. 7,000 + 400 + 50 + 2 c. (7 ∗ 1,000) + (4 ∗ 100) + (5 ∗ 10) + (2 º 1) d. (7 ∗ 103) + (4 ∗ 102) + (5 ∗ 101) + (2 ∗ 100) Math Masters, p. 196 187-220_EMCS_B_MM_G5_U07_576973.indd 196 556 Unit 7 3/29/11 2:03 PM Exponents and Negative Numbers V I S U A L SMALL-GROUP ACTIVITY 15–30 Min To provide language support for number notations, ask students to compare and contrast the terms standard notation and exponential notation. Have students use the Venn diagram found on Differentiation Handbook, page 149. See the Differentiation Handbook for more information. 5,000 + 300 + 10 + 4 (5 ∗ 1,000) + (3 ∗ 100) + (1 ∗ 10) + (4 ∗ 1) (5 ∗ 103) + (3 ∗ 102) + (1 ∗ 101) + (4 ∗ 100) 2,000 + 700 + 50 + 6 T A C T I L E (Differentiation Handbook, p. 149) 5,314 b. for Numbers Write each number below in the other three possible ways, as shown above. 1. a. K I N E S T H E T I C ELL SUPPORT Time Writing in Expanded Notation A