Math Module 3 Multi-Digit Multiplication and Division Topic F: Reasoning with Divisibility Lesson 24: Determine whether a whole number is a multiple of another number. 4.OA.4 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 24 Target Determine whether a whole number is a multiple of another number. •3 •6 •9 • 12 •9 •6 •9 • 12 • 15 • 18 • 15 • 12 • 15 • 18 • 21 • 24 • 21 • 18 • 15 • 12 • 15 • 18 • 21 • 24 • 27 • 24 • 21 • 24 • 27 • 30 Group Counting (5 minutes) • Count by threes to 30 and change directions when you see the arrow. You did it! Fluency Lesson 24 •5 • 10 • 15 • 20 • 15 • 10 • 15 • 20 • 25 • 30 • 25 • 20 • 25 • 30 • 35 • 40 • 35 • 30 • 25 • 20 • 25 • 30 • 35 • 40 • 45 • 40 • 35 • 40 • 45 • 50 Group Counting (5 minutes) • Count by fives to 50 and change directions when you see the arrow. You did it! Fluency Lesson 24 •2 •4 •6 •8 •6 •4 •6 •8 • 10 • 12 • 10 •8 • 10 • 12 • 14 • 16 • 14 • 12 • 10 •8 • 10 • 12 • 14 • 16 • 18 • 16 • 14 • 16 • 18 • 20 Group Counting (5 minutes) • Count by twos to 20 and change directions when you see the arrow. You did it! Fluency Lesson 24 • 10 • 20 • 30 • 40 • 30 • 20 • 30 • 40 • 50 • 60 • 50 • 40 • 50 • 60 • 70 • 80 • 70 • 60 • 50 • 40 • 50 • 60 • 70 • 80 • 90 • 80 • 70 • 80 • 90 • 100 Group Counting (5 minutes) • Count by tens to 100 and change directions when you see the arrow. You did it! Fluency Lesson 24 •4 •8 • 12 • 16 • 12 •8 • 12 • 16 • 20 • 24 • 20 • 16 • 20 • 24 • 28 • 32 • 28 • 24 • 20 • 16 • 20 • 24 • 28 • 32 • 36 • 32 • 28 • 32 • 36 • 40 Group Counting (5 minutes) • Count by fours to 40 and change directions when you see the arrow. You did it! Fluency Lesson 24 •6 • 12 • 18 • 24 • 18 • 12 • 18 • 24 • 30 • 36 • 30 • 24 • 30 • 36 • 42 • 48 • 42 • 36 • 30 • 24 • 30 • 36 • 42 • 48 • 54 • 48 • 42 • 48 • 54 • 60 Group Counting (5 minutes) • Count by sixes to 60 and change directions when you see the arrow. You did it! Fluency Lesson 24 Fluency Lesson 24 Prime or Composite? Prime or 5 Composite Write the factor pair. Fluency Lesson 24 Prime or Composite? Prime or 15 Composite Write the factor pairs. Fluency Lesson 24 Prime or Composite? Prime or 12 Composite Write the factor pairs. Fluency Lesson 24 Prime or Composite? Prime or 19 Composite Write the factor pair. Fluency Lesson 24 Prime or Composite? Prime or 24 Composite Write the factor pairs. Fluency Test for Factors 30 45 48 56 • Write down the numbers that have 10 as a factor. Lesson 24 Fluency Test for Factors Lesson 24 • Write the division equations that prove both 5 and 6 are factors of 30. 5=6 Fluency Test for Factors 30 45 48 56 • Write down the numbers that have 6 as a factor. Lesson 24 Fluency Test for Factors 30 = 3 x 10 = 3 x (2 x 5) = (3 x 2) 5 Lesson 24 • Prove that both 3 and 2 are factors of 30 using the associative property. Fluency Test for Factors 48 = 24 x 2 = (8 x 3) x 2 = 8 x (3 x 2) Lesson 24 • Prove that both 3 and 2 are factors of 48 using the associative property. Fluency Test for Factors 56 45 48 30 • Write down the numbers that have 8 as a factor. Lesson 24 Fluency Test for Factors 48 = 24 x 2 = (6 x 4) x 2 = 6 x (4 x 2) Lesson 24 • Prove that both 4 and 2 are factors of 48 using the associative property. Fluency Test for Factors 56 = 28 x 2 = (7 x 4) x 2 = 7 x (4 x 2) Lesson 24 • Prove that both 4 and 2 are factors of 56 using the associative property. Application Problem 5 minutes 8 cm × 12 cm = 96 square centimeters. Imagine a rectangle with an area of 96 square centimeters and a side length of 4 centimeters. What is the length of its unknown side? How will it look when compared to the 8 by 12 rectangle? Draw and label both rectangles. Lesson 24 Concept Development Lesson 24 Problem 1: Determine the meaning of the word multiple. • Turn to your partner and count by fours, taking turns with each new number. So, for example, you start by saying 0, your partner says 4, then you say 8. You have Stop! What Your one minute. Ready? Begin. Tell me some number did things you turn! you count up noticed! to? Go! 80 24 16 412 20 28 Concept Development We started by saying the 4 times table, then kept adding on 4. When we got to 100, the counting started over again. Lesson 24 Problem 1: Determine the meaning of the word multiple. Just like we started with 0, 4, 8, 12, after 100 it was 104, 108, 112, and so on. There was a pattern with how the numbers ended. Concept Development Problem 1: Determine the meaning of the word multiple. When we skip-count by aThose whole arenumber, nice observations. Let’s try that the numbers that we again, where saybeginning are called you leftmultiples. off. This time, as you count, think about Talk patterns to yourthere partner what are. about what you Ready? Begin. noticed. Lesson 24 Lesson 24 Concept Development All of the multiples of 4 were even numbers. No matter how high we counted we kept adding on 4 more. Problem 1: Determine the meaning of the word multiple. The digit in the ones place of every number followed its own pattern. It went 0, 4, 8, 2,6 over and over again. Concept Development Lesson 24 Problem 1: Determine the meaning of the word multiple. • Study this visually. This pattern in the ones place continues forever! Why? • Because it is always 4 more. If that’s what has been happening, then the same things will keep happening. It worked up to 1 hundred, and the ones and tens place will continue with the same pattern, so it will even work in the two hundreds and three hundreds. 4 times 25 is 100, so then in every hundred it repeats, and so it just keeps going in cycle! • How is a multiple different from a factor? • When we found the factors of a number, we listed them and then we were done. With multiples, we could keep going forever and ever! Concept Development Lesson 24 Problem 2: Determine if one number is a multiple of another number and list multiples of given numbers. When we count that! Use the by we get No,fours because we Try We 96 isto a associativeknow property to 24.skip-count 4 times 6 Yes, because for can’t of 4by see if 96multiple is divisible What somefrom it is beyond isby 24. Four is3.a Remember, ourknow five totimes 24. I used long we Yes! Eight We can divide tomental see ifIsmath. 96 about 8? How Why 24 is a24 Application factor of 24. 24 divided by 5 that 8 times 12 and 4 And 3 is isdivision. 24. Well, 8 divisible by 3. We might can we find out if Problem, since 4 Is 24 a times 24 are 96 from the a multiple multiple has a also the is a factor of 24, 96times is a multiple 24 is 96.of use the associative Application Problem. multiple of 4? 3? 5? associative so remainder. 24 must be a What did we do property since we know Also, 5 is of a not of to figure that property. multiple 8. 12 and that 8 times 4 8? out? a factor of 24. times 24 are 96 from the Application Problem. Lesson 24 Since zero times any number is Concept Development Problem 2: Determine if one number is a multiple of another number and list multiples of given numbers. zero, zero is a multiple of every number. So we could consider it There was no the first multiple of every number. No. It’s less. But remainder so 30isa However, when we skip-count, we But If isn’t you 3, 6, 9,the3number IsWhat 96 afirst List the 0Yes? times is 0, so usually start with What did What is the multiple count byof 32 factor of 96. Yes! 32! 3. number did multiple of five we’re counting So, we usually 12,by. 15. you factor pair 3? three Should times maybe? 96 a you begin both 3 and multiples of think of the That numbermakes itself, in this discover? of 3? we will start youwith get with? 32? 3. case 3, as the first multiple, multiple 0of 3. to first? 96? instead of 0. That way, the first multiple is 1 × 3, the second is 2 × 3, and so on. Concept Development (Optional) Lesson 24 Problem 3: Use the associative property to see that any multiple of 6 is also a multiple of 3 and 2. • • • • • • Shout out a multiple of 6. Is any multiple of 6 also a multiple of 2 and 3? Let’s use the associative property (and commutative property) to find out. 60 = 10 × 6 = 10 × (2 × 3) = (10 × 2) × 3= 20 × 3 Yes, 60 is a multiple of 3. If we count by 3 twenty times, we get to 60. • = (10 × 3) × 2= 30 × 2 Yes, 60 is a multiple of 2. If we count by 2 thirty times, we get to 60. • Let’s use a letter to represent the number of sixes to see if this is true for all sixes. Concept Development (Optional) Lesson 24 Problem 3: Use the associative property to see that any multiple of 6 is also a multiple of 3 and 2. • n × 6 = n × (2 × 3) • n × 6 = (n × 2) × 3 • n × 6 = (n × 3 ) × 2 • Discuss with your partner why these equations are true. You might try plugging in 4 or 5 as the number of sixes, n, to help you understand. • It takes twice as many threes to get to the multiple as sixes. It’s double the number of multiples of six, 2 × n. And it’s three times as many twos to get there! It’s because twos are smaller units so it takes more. • So maybe the multiples of a number are also the multiples of its factors. Problem Set 10 Minutes Problem Set • In Problem 1, which multiples were the 10 Minutes easiest to write, the fives, fours, or sixes? Why? What strategy did you use in Problem 2? Problem Set 10 Minutes Problem Set 10 Minutes In Problem 5 (c) and (d), what patterns did you discover about multiples of 5 and 10? Debrief Lesson Objective: Determine whether a whole number is a multiple of another number. • Explain the difference between factors and multiples. • Which number is a multiple of EVERY number? • How can the associative property help you to know if a number is a multiple of another number? • Did anybody answer “no” on Problem 4? What about 1? Are prime numbers multiples of 1? • In the lesson we found that when counting by fours, the multiples followed a pattern of having 0, 4, 8, 2, and 6 in the ones digit. Does that mean any even number is a multiple of 4? Exit Ticket Lesson 1