Math Module 3 Multi-Digit Multiplication and Division Topic E: Division of Tens and Ones with Successive Remainders Lesson 20: Solve division problems without remainders using the area model. 4.OA.3 4.NBT.6 PowerPoint designed by Beth Wagenaar Material on which this PowerPoint is based is the Intellectual Property of Engage NY and can be found free of charge at www.engageny.org Lesson 20 Target You will solve division problems without remainders using the area model. Fluency Development Lesson 20 Divide using the standard algorithm. 67 ÷ 2 (2 x 33) + 1 = 67 67 33 1 Fluency Development Lesson 20 Divide using the standard algorithm. 60 ÷ 4 (15 x 4) + 0 = 60 60 60 0 Fluency Development Lesson 20 Divide using the standard algorithm. 29 ÷ 3 (3 x 9) + 2 = 29 29 27 2 Fluency Development Lesson 19 Divide using the standard algorithm. 77 ÷ 4 (19 x 4) + 1 = 77 77 76 1 Lesso Fluency Development Find the Unknown Factor. 15 ÷ 3 = 5 5 x ___ = 15 Lesso Fluency Development Find the Unknown Factor. 12 ÷ 4 = 3 4 x ___ = 12 Lesso Fluency Development Find the Unknown Factor. 35 ÷ 5 = 7 5 x ___ = 35 Lesso Fluency Development Find the Unknown Factor. 36 ÷ 6 = 6 6 x ___ = 36 Lesso Fluency Development Find the Unknown Factor. 49 ÷ 7 = 7 7 x ___ = 49 Lesso Fluency Development Find the Unknown Factor. 81 ÷ 9 = 9 9 x ___ = 81 Lesso Fluency Development Find the Unknown Factor. 48 ÷ 6 = 8 6 x ___ = 48 Lesso Fluency Development Find the Unknown Factor. 42 ÷ 7 = 6 7 x ___ = 42 Lesso Fluency Development Find the Unknown Factor. 54 ÷ 9 = 6 9 x ___ = 54 Fluency Mental Multiplication Say the multiplication sentence in in unit unit form. form. sentence 3 tens tens xx 22 =tens =6 3 6 tens. 3 ones x 2 = 6 ones. hundreds. 3 x 2 = ___ 30 x 2 = ___ 30 x 20 = ___ Fluency Mental Multiplication Say the multiplication sentence in in unit unit form. form. sentence 4 tens x 2 tens = 8 4 tens onesxx22==88tens. ones. hundreds. 4 x 2 = ___ 40 x 2 = ___ 40 x 20 = ___ Fluency Mental Multiplication Say the multiplication sentence in in unit unit form. form. sentence 5 tens x 3 tens = 15 5 5tens x 3x =3 15 tens. ones = 15 ones. hundreds. 5 x 3 = ___ 50 x 3 = ___ 50 x 30 = ___ Application Problem 5 Minutes Write an equation to find the unknown length of each rectangle. Then find the sum of the two unknown lengths. Lesson 20 Application Problem 5 Minutes Write an equation to find the unknown length of each rectangle. Then find the sum of the two unknown lengths. Lesson 20 Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Draw a rectangle with an area of 48 square units and a width of 4 units. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Draw a number bond to match the whole and parts of the rectangle. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Let’s find the unknown side lengths of the smaller rectangles and add them. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Take a moment to record the number sentences, reviewing with your partner their connection to both the number bond and the area model. What is 10 and 2? What is 8 ÷ 4? What is 48 of divided by 4? side? What is the length the unknown Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Work with your partner to partition the same area of 48 as 2 twenties and 8. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Try to find another way to partition the area of 48 so it’s easy to divide. You have 4 minutes – get to work! Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) 30II did and 18 T: Draw a new rectangle with the same area directly below but bydon’t 4to match the areas of the saiditpartitioned 24 +using 24. work 24 well because rectangles in Part (a) of the Application Problem. rectangles, with divided by 4each is30 6.has 6 + a6 Did anyone find remainder when you an area of 12 square is 12. another way to divided it by 4. units. 12+12+12+12. partition the area of 48 it’s easy to divide? Concept Development Lesson 20 Problem 1: Decompose 48 ÷ 4 from whole to part. • Explain to your partner why different ways of partitioning give us the same correct side length. I use the same break sumofof4 the You can take a total, Drawapart a rectangle with an area of 48 square units and aThe width units. and distribute lengths is the break it into two parts, S: (Draw.) strategy to find the same as the andareas divideofeach T: Draw a newto rectangle the of answer 56 ÷ 8. with the same area directly below but partitioned to match the whole length them separately. rectangles40in÷Part 8 is (a) 5. of the Application Problem. 16 ÷ 8 is 2. 5 and 2 makes 7. You are starting with the same amount of area but just chopping it up differently. Repeat the process we just Remember Part B of our used to partition the Application Problem? area of 96. 5 Minutes Find a different to Write anway equation to find the unknown length of decompose each rectangle. Then find the sum of the two the problem. unknown lengths. Lesson 20 Concept Development Lesson 20 Problem 2: Decompose 96 ÷4 from whole to part. • How did you partition the area of 96? Did anyone chop 96square into units and a width of 4 units. Draw a•rectangle with an area of 48 S: (Draw.) 40 + 40 + 16. It was just T: Draw a new likerectangle 48 ÷ 4.with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Lesson 20 Concept Development Problem 2: Decompose 96 ÷4 from whole to part. • Did anyone partition 96 into 4 twenties and 2 eights? Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. 4 twenties 2 eights Concept Development Lesson 20 Problem 2: Decompose 96 ÷4 from whole to part. • Who made 96 into 2 forty-eights and used our answer from 48 ÷ 4? All you had to do was double it. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. 96 ÷ 4 • Thinking about area, let’s try a new way to divide. The expression 96 ÷ 4 describe rectangle with anand area of 96 Draw acan rectangle with anaarea of 48 square units a width of 4square units. units. We are trying S: (Draw.) to find out the length of the unknown side. T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the • What is the known side length? rectangles in Part (a) of the Application Problem. • 4. Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. 96 ÷ 4 • 4 times how many tens gets us as close as possible to an area of 9 tens? Draw a rectangle with an area of 48 square units and a width of 4 units. • 2 tens. S: (Draw.) • Let’s give 2 tens to the T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the length. rectangles in Part (a) of the Application Problem. • Let’s record the 2 tens in the tens place. • What is 4 times 2 tens? Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. 96 ÷ 4 Draw a• rectangle 8 tens.with an area of 48 square units and a width of 4 units. S: (Draw.) • a How many square unitsarea directly below but partitioned to match the areas of the T: Draw new rectangle with the same rectanglesisinthat? Part (a) of the Application Problem. • 80 square units. • How many tens remain? • 1 ten. Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. 96 ÷ 4 Draw •a rectangle withthe an area of 48 square units and a width of 4 units. Let’s add remaining S: (Draw.) the 6with ones. T: Draw aten new to rectangle the What same area directly below but partitioned to match the areas of the rectanglesisin1Part Application Problem. ten(a)+of6 the ones? • 16. Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. • We have 16 square units remaining with a width of 4. • 4 times how many ones gets us as close as possible to an area of 16 ones? Draw a rectangle with an area of 48 square units and a width of 4 units. • 4 ones. S: (Draw.) T: Draw•a new rectangle the same area directly below but partitioned to match the areas of the Let’s give 4with ones to the length. rectangles in Part (a) of the Application Problem. • What is 4 times 4? • 16. We have 16 square units. • We have no more area to divide. • Tell me the length of the unknown side. • 24! • Our quotient tells us that length. Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. • How can we express the length of the unknown side using the distributive Draw a rectangle with an areaproperty? of 48 square units and a width of 4 units. S: (Draw.) • (80 ÷ 4) + (16 ÷ 4) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the With arrows to connect the distributive rectangles•in Part (a)your of the partner, Applicationdraw Problem. property and the area model. Concept Development Lesson 20 Problem 3: Compose 96 ÷4 from part to whole.. Draw a rectangle with an area of 48 square units and a width of 4 units. S: (Draw.) T: Draw a new rectangle with the same area directly below but partitioned to match the areas of the rectangles in Part (a) of the Application Problem. Concept Development Problem 3: Compose 96 ÷4 from part to whole.. • Review our four drawings and our process with your partner. Try to reconstruct what we did step by step before we try another one. We solved 96 divided by 4 in two very different ways using the area model. First, we started with the whole rectangle and partitioned it. The second way was to go one place value at a time and make the whole rectangle from parts. We’re ready! Bring it on! Lesson 20 Problem Set 10 Minutes Problem Set 10 Minutes Problem Set 10 Minutes • In Problem 2, did you partition the rectangle the same way as your partner? Why were we able to go from whole to part? Problem Set 10 Minutes • In Problems 2 and 3, explain the connection between the written method, the number bond, and the area model. Problem Set 10 Minutes Debrief Lesson Objective: Solve division problems without remainders using the area model. • In the last problem, explain the connection between the algorithm and the area model. • Each time we divide, what happens to the amount of area we still have left to divide? • Even though division is messy, I think it is the most interesting operation of all because, imagine this, sometimes that little piece that is left to divide is always there, even though it gets infinitely small! • Talk to your partner about what you think I might mean by that. Exit Ticket Lesson 1