Numeration and Place Value Objective To review place value in 2-digit and 3-digit numbers. www.everydaymathonline.com ePresentations eToolkit Algorithms Practice EM Facts Workshop Game™ Teaching the Lesson Key Concepts and Skills • Count by 1s, 10s, and 100s with base-10 blocks. [Number and Numeration Goal 1] • Explore place-value concepts with base-10 blocks; read and write 2- and 3-digit numbers. [Number and Numeration Goal 2] • Build numbers with base-10 blocks in preparation for modeling addition strategies. [Number and Numeration Goal 2] Key Activities Children explore base-10 blocks, matching numbers to them and modeling 2- and 3-digit numbers (with and without zero). Ongoing Assessment: Informing Instruction See page 187. Family Letters Assessment Management Common Core State Standards Ongoing Learning & Practice 1 2 4 3 Playing the Digit Game My Reference Book, pp. 132 and 133 per partnership: 4 each of number cards 0–9 (from the Everything Math Deck, if available) Children practice forming and comparing numbers. Math Boxes 3 1 Math Journal 1, p. 54 Children practice and maintain skills through Math Box problems. Home Link 3 1 Curriculum Focal Points Interactive Teacher’s Lesson Guide Differentiation Options READINESS Counting Practice calculator base-10 blocks (10 flats, 10 longs, 10 cubes) Children use their calculators to investigate place value. ENRICHMENT Creating 3-Digit Numbers number cards 1–9 (from the Everything Math Deck, if available) Children create as many numbers as possible using three digits. Math Masters, p. 57 Children practice and maintain skills through Home Link activities. Ongoing Assessment: Recognizing Student Achievement Use journal page 53. [Number and Numeration Goal 2] Key Vocabulary base-10 system Materials Math Journal 1, p. 53 My Reference Book, p. 11 Math Masters, p. 427 transparency of Math Masters, p. 56 (optional) base-10 blocks number cards 0–9 (from the Everything Math Deck, if available) calculator Advance Preparation You may want to spend two days on this lesson. For Part 1, you and each child or partnership will need a set of base-10 blocks (3 or 4 flats, 10 longs, and 10 cubes in bags labeled with children’s tool-kit numbers). To display a Place-Value Mat, make an overhead transparency of Math Masters, page 56 or draw a Place-Value Mat on the board. For a mathematics and literacy connection, obtain a copy of A Place for Zero: A Math Adventure by Angeline Sparagna LoPresti (Charlesbridge Publishing, 2003). Teacher’s Reference Manual, Grades 1–3 pp. 30, 56, 57 184 Unit 3 Place Value, Money, and Time 184_EMCS_T_TLG1_G2_U03_L01_576949.indd 184 2/11/11 9:12 AM Getting Started Mental Math and Reflexes Math Message Pose number stories that involve addition and subtraction facts. Suggestions: Keisha read 8 pages of her book last night and 6 pages this morning. How many pages did she read in all? 14 pages Hana scored 7 points. Dakota scored 9. How many points did they score in all? 16 points 52 = 5 25 = 2 tens and 2 ones tens and 5 ones Austin brought 17 cupcakes to school for his birthday. He gave 8 to his classmates. How many cupcakes does he have left? 9 cupcakes 1 Teaching the Lesson Math Message Follow-Up ● On WHOLE-CLASS DISCUSSION Briefly discuss children’s responses. Ask children to explain how they decided which digit names the tens and which digit names the ones. These numbers will be revisited later in the lesson. Explain to children that in today’s lesson they will use base-10 blocks to create numbers. Exploring a Simple Way to Day 1 of this lesson, children should complete the Math Message Follow-Up, explore drawing base-10 blocks, and begin matching numbers and displays of base-10 blocks. ● On Day 2 of this lesson, children should continue matching numbers and displays of base-10 blocks and do place-value exercises. Then have children complete Part 2 activities. Interactive whiteboard-ready ePresentations are available at www.everydaymathonline.com to help you teach the lesson. WHOLE-CLASS ACTIVITY Draw Base-10 Blocks (My Reference Book, p. 11) Hold up a cube, a long, and a flat. Say: These are called base-10 blocks. Hold up a cube. Say: This is a base-10 cube. It represents one. Then hold up a long and say: This is a long. It represents ten. Ask children why they think a long represents ten. Because it is made up of 10 cubes Last, hold up a flat and say: This is a flat. It represents one hundred. Ask children why they think a flat represents one hundred. Because it is made up of 100 cubes Display the blocks on the overhead projector. Remind children that our system for writing numbers is called the base-10 system, because it is based on grouping things by tens. Explain that base-10 blocks are useful for understanding numbers and solving problems. Base-10 blocks cube flat Base-10 drawings Show children the pictures in the margin as a quick and easy way to draw base-10 blocks. Drawing pictures may be more convenient than using the actual blocks, and pictures are often useful for explaining and recording solutions. Read about base-10 blocks with your class on page 11 of My Reference Book. long cube long flat Lesson 3 1 EM3cuG2TLG1_185-189_U03L01.indd 185 185 12/12/10 1:32 PM NOTE Children use 10 number cards, a Place-Value Mat, a calculator, and many base10 blocks for these activities. Before beginning this activity, you may want to show children how to arrange these materials on their desks. If necessary, children can work in pairs. NOTE To review writing 2-digit number words, consider varying the Matching Numbers and Displays of Base-10 Blocks activity. Have children work in partnerships. One partner shows a 2-digit number by placing base-10 blocks on a Place-Value Mat. The other partner writes the number word for that number on his or her slate. Then partners reverse the procedure. One partner writes a 2-digit number word on his or her slate and the other partner forms the number with the base-10 blocks and Place-Value Mat. Ongoing Assessment: Informing Instruction Watch for children who enter 7008 on the calculator. When representing 708 with base-10 blocks, be sure to point out that there are three columns on the Place-Value Mat, therefore there should only be 3 digits. Teaching Aid Master-Name Date Time ones Place-Value Mat Matching Numbers and WHOLE-CLASS ACTIVITY Displays of Base-10 Blocks (Math Masters, pp. 56 and 427) Give each child or partnership a set of number cards (0–9) and a Place-Value Mat. Display 3 flats, 5 longs, and 2 cubes on a PlaceValue Mat. (See Advance Preparation.) Have children show the number 352 by putting cards on their Place-Value Mats. Children show 352 by putting the card for 3 in the hundreds place, the card for 5 in the tens place, and the card for 2 in the ones place. Ask: How many hundreds are in this number? 3 How many tens? 5 How many ones? 2 Then ask children to read the number in unison. Three hundred fifty-two Repeat with other 2- and 3-digit numbers, including the numbers 52 and 25 from the Math Message. Ask children to explain what the digits 5 and 2 mean in each number. Display the place-value blocks at random without the mat. By doing this, children will have to sort the blocks mentally into ones, tens, and hundreds. Then reverse the procedure. Write a 2- or 3-digit number on the board and ask children to show the number by placing base-10 blocks on their Place-Value Mats. Repeat with several other 2- or 3-digit numbers. Now, repeat the previous procedures using numbers with zero in the tens or ones place. For example, display 3 flats and 4 cubes and ask children to use number cards to show the number on their Place-Value Mats. Some children may put no digit card in the tens column; others will put a zero. Point out that not including the zero can cause problems when there is no Place-Value Mat. Write 34 and 304 on the board and ask which number matches the base-10 blocks. 304 Ask which digit in 304 shows that there are no longs. The zero Continue with a series of translations among spoken numbers, written numbers, base-10 blocks, number cards, and calculator displays. For example: Say: Show the number 508 with base-10 blocks. 5 flats, 8-cubes Say: Use cards to show the number with 4 in the ones place, 0 in the tens place, and 8 in the hundreds place. 804 tens Ask: In 567, which number is in the ones place? 7 The tens place? 6 The hundreds place? 5 Write 749 on the board. Say: Read the number on the board. Seven hundred forty-nine. hundreds Say: Use your calculator. Enter 708. Now use base-10 blocks to show 708. 7 flats, 8 cubes Math Masters, p. 427 186 Unit 3 Place Value, Money, and Time 185-189_EMCS_T_TLG1_G2_U03_L01_576949.indd 186 2/11/11 9:19 AM Student Page Using Place Value to Compare Numbers Date 31 Write the numbers 549 and 547. Ask a volunteer to read the numbers. Ask: Which is greater? 549 How can you tell? Answers will vary. One possible strategy is to write the numbers one under the other, so that same-place digits are aligned, and then compare the values of the aligned pairs of digits starting with the first pair on the left. (See margin.) For example: The hundreds digits are the same; each has a value of 500. The tens digits are the same; each has a value of 40. The ones digits are not the same; 9 is greater than 7. So 549 is greater than 547. Write 549 > 547. Repeat with other 3-digit numbers. Doing Place-Value Exercises Time LESSON Place Value Write the number for each group of base-10 blocks. 547 1. 403 2. 3. Write a number with … 4. 5 in the ones place, 3 in the hundreds place, and 2 in the tens place. > 322 How many ones? 6. 122 > 102 5 0 6 How many tens? 325 Write <, >, or =. 5. 328 506 How many hundreds? 7. 623 < 633 8. Marta wrote 24 to describe the number shown by these INDEPENDENT ACTIVITY base-10 blocks: (Math Journal 1, p. 53) Is Marta right? Explain your answer. Children use base-10 blocks to complete journal page 53. Then review the answers with them. For Problem 3, make sure children have written 325 and not 532 or 235. Ask a volunteer to explain the answer to Problem 8. Have other children explain why they agree or disagree with the answer. Make sure children are able to identify each of the base-10 materials in the pictures. Sample answer: No; the base-10 blocks show 2 hundreds, not 2 tens. Math Journal 1, p. 53 EM3cuG2MJ1_U03_53-79.indd 53 12/18/10 11:46 AM 5 4 9 Ongoing Assessment: Recognizing Student Achievement Use journal page 53, Problems 1 and 3 to assess children’s understanding of place value. Children are making adequate progress if they can correctly answer the problems using base-10 blocks. Some children may be able to complete the problems that involve 0 as a placeholder. [Number and Numeration Goal 2] 2 Ongoing Learning & Practice Playing the Digit Game NOTE You may wish to have children review expanded notation, which involves a knowledge or understanding of place value. Expanded notation is a way of writing a number as the sum of the values of each digit. Student Page Games The Digit Game PARTNER ACTIVITY (My Reference Book, pp. 132 and 133) Have children read the rules for the Digit Game on pages 132 and 133 of My Reference Book. Explain to children that they will play the game with 3 cards, using them to make the largest possible 3-digit number. Play several demonstration hands with the class. Have partners play several rounds of the game. 5 4 7 Journal page 53 Problems 1 and 3 Materials ❑ number cards 0–9 (4 of each) Players 2 Skill Making and comparing numbers Object of the game To collect more cards. Directions 1. Shuffle the cards. Place the deck number-side down on the table. 2. Each player draws 2 cards from the deck and uses them to make the larger 2-digit number. 3. The player with the larger number takes all 4 cards. 4. The game is over when all of the cards have been used. 5. The player with more cards wins. My Reference Book, p. 132 Lesson 3 1 185-189_EMCS_T_TLG1_G2_U03_L01_576949.indd 187 187 1/24/11 1:58 PM Student Page Date Time LESSON Math Boxes 3 1 Math Boxes 31 calculator to count by 7s. 9+7 Rule +7 7 > 10 + 12 21 14 (Math Journal 1, p. 54) 2. Write <, >, or =. 1. Fill in the frames. Use your 7+7 13 < 26 = 5+9 Mixed Practice Math Boxes in this lesson are paired with Math Boxes in Lesson 3-3. The skills in Problems 5 and 6 preview Unit 4 content. 42 35 28 9 98 99 3. Solve. 4. How much money? Fill in the Unit $21.40 B $21.45 18 + 9 = Change 17 + 9 = End +10¢ 16 + 9 = ? 15 + 9 = Answer: 17 ¢ Home Connection Children continue their work with base-10 blocks as they complete place-value exercises similar to those on journal page 53. D $11.40 6. Solve. How much does he have now? 7¢ INDEPENDENT ACTIVITY (Math Masters, p. 57) A C $2.45 Start Home Link 3 1 circle next to the best answer. 15 70 + 80 = 150 700 + 800 = 1,500 7,000 + 8,000 = 15,000 7+8= 5. Mike had 7¢. He found a dime. INDEPENDENT ACTIVITY Unit 27 26 25 24 3 Differentiation Options 116 Math Journal 1, p. 54 EM3cuG2MJ1_U03_53-79.indd 54 12/18/10 11:46 AM READINESS Counting Practice SMALL-GROUP ACTIVITY 5–15 Min To explore place value using a concrete model, have children use a calculator and base-10 blocks in a counting activity. Begin by reviewing how to count by 1s on the calculator. The following program will work on any calculator: Clear the calculator. + + Press 0 + 1 1 1 .… Two additional programs for counting by 1s are given below for demonstration purposes. Have children perform the steps on their own calculators. Home Link Master Name Date HOME LINK 31 䉬 Family Note For the Texas Instruments TI-108: Time ON/C Place Value 1. Press All numbers are made up of digits. The value of a digit depends on its place in the number. In the number 704, the digit 7 means 7 hundreds, the digit 0 means 0 tens, and the digit 4 means 4 ones. This idea is called place value. 2. Press 0. This is the starting number. Your child has been using base-10 blocks to help him or her understand the idea of place value. Base-10 blocks are shown in Problems 1a and 1b below. A “cube” (with each side 1 unit long) represents 1. A “long” (a rod that is 10 units long) represents 10. And a “flat” (a square with each side 10 units long) represents 100. 10 11 Please return this Home Link to school tomorrow. 3. Press + . This clears your calculator. . This tells the calculator to count up. 4. Press 1. This tells the calculator to count by 1s. 1. Which number do the base-10 blocks show? a. 374 b. 507 2. Write a number with 740 4. In 806, how many hundreds? How many tens? How many ones? 1. Press 3. Write a number with 7 in the hundreds place, 0 in the ones place, and 4 in the tens place. For the Casio SL-450: 3 in the tens place, 6 in the ones place, and 9 in the hundreds place. . This clears your calculator. 2. Press 1. This tells the calculator to count by 1s. 936 8 0 6 5. In 231, how many hundreds? How many tens? How many ones? 2 3 1 3. Press . This tells the calculator to count up. 4. Press 0. This is the starting number. Math Masters, p. 57 188 Unit 3 Place Value, Money, and Time EM3cuG2TLG1_185-189_U03L01.indd 188 12/20/10 4:42 PM Now the calculator is ready to start counting by 1s. Without clearing their calculators, have children press the key. Press the key repeatedly together as the class counts together by 1s stopping at 9. Ask children what comes next. Then have them press once, observing the change from 9 to 0 in the ones place and the appearance of a 1 in the tens place. What does the 1 stand for? 1 ten Clear the calculators and repeat the counting by 1s activity. This time, have the children work in partnerships. One partner does the calculator count while the other partner takes a cube each time one more is added. Compare what happens after 9 is displayed on the calculator (changing to 10) and the exchange of ten single cubes for one long. Repeat the counting activity having all children count by 10s on the calculator from 0 to 100. Now have partnerships repeat the count switching roles so one partner counts on the calculator and the other partner takes longs. Repeat with 100s and flats. If interest and time permit, change the start number and repeat counts by 10s and 100s using both the calculator and the blocks— for example, start at 14 (1 long, 4 cubes) and count by 10s (adding one long each time). ENRICHMENT Creating 3-Digit Numbers SMALL-GROUP ACTIVITY 5–15 Min To further explore 3-digit numbers, have children create as many 3-digit numbers as possible using the same three nonzero digits. Each child selects three cards from the Everything Math Deck (1–9). They create as many numbers as possible using the three cards and record their answers. Try three different cards. Ask: How many combinations are possible using three cards? 6 Have children try four cards. How many combinations are possible using four cards? 24 Planning Ahead Before beginning Lesson 3-2, make an overhead transparency of Math Masters, page 58, the Fruit and Vegetables Stand Poster. Lesson 3 1 EM3cuG2TLG1_185-189_U03L01.indd 189 189 12/12/10 1:32 PM