Mathematics Grade 4 – Unit 1 (SAMPLE) Unit 1: Multiples and Factors Possible time frame: 10 days In this unit students develop understanding of multiples and factors, applying their understanding of multiplication from the previous year. This understanding lays a strong foundation for students to develop, discuss, and use efficient, and accurate, computational strategies involving multi-digit numbers. These concepts and the terms “prime” and “composite” are new to Grade 4, so they are introduced early in the year to give students ample time to develop and apply understanding. Supporting Cluster Standards Gain familiarity with factors and multiples. 4.OA.B.4 Find all factor pairs for a whole number in the range 1-100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1-100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1-100 is prime or composite. Standards Clarification For assessment purposes, one or both factors should be greater than 5. Additional Cluster Standards Standards Clarification Generate and analyze patterns. 4.OA.C.5 Generate a number or shape pattern that follows a given rule. Identify apparent features of the pattern that were not explicit in the rule itself. For example, given the rule, “Add 3” and the starting number 1, generate terms in the resulting sequence and observe that the terms appear to alternate between odd and even numbers. Explain informally why the numbers will continue to alternate in this way. While working on 4.AO.C.5, students use manipulatives to determine whether a number is prime or composite. Although there are shape patterns in arrays, the focus of this unit is number patterns. 4.OA.C.5 is repeated in Unit 13, where the focus will be on identifying shape patterns. Focus Standards for Mathematical Practice MP.3 Construct viable arguments and critique the reasoning of others. MP.7 Look for and make use of structure. The focus of this unit is to use student’s understanding of the concept and language to discuss the structure of multiples and factors. (MP.3, MP.7) Review the Grade 4 sample year-long scope and sequence associated with this unit plan. 1 Mathematics Grade 4 – Unit 1 (SAMPLE) What will students know and be able to do by the end of this unit? Students will demonstrate an understanding of the unit focus and meet the expectations of the Common Core State Standards on the unit assessments. Standards Unit Assessment Objectives and Formative Tasks The standards for this unit include: Students will demonstrate mastery of the content through assessment items and tasks requiring: Objectives and tasks aligned to the CCSS prepare students to meet the expectations of the unit assessments. 4.OA.B.4 Find all factor pairs for a whole number in the range 1-100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1-100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1-100 is prime or composite. • • • • Conceptual Understanding Procedural Skill and Fluency Application Math Practices Concepts and Skills Each objective is broken down into the key concepts and skills students should learn in order to master objectives. 4.OA.C.5 Generate a number or shape pattern that follows a given rule. Identify apparent features of the pattern that were not explicit in the rule itself. 2 Mathematics Grade 4 – Unit 1 (SAMPLE) Sample End-of-unit Assessment Items: 1) What factor of 12 is missing in the list of numbers? 1, 2, 3, 4, _____, 12 2) 3) On the chart, circle all the numbers that have 4 as a factor. 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Which of these numbers is a prime number? A. 4) 17 6 B. 27 C. 67 D. 81 The pattern below is found by adding 5 to the first term to get the second term. Then subtract 2 from the second term to get the third term. The pattern of adding 5, then subtracting 2 to get the next two terms continues. Write the next two numbers in the number pattern. 1 6 4 9 7 12 10 _____ _____ Explain why after the first term of 1, the pattern alternates with 2 evens then 2 odds. 5) The table below shows some number pairs. The following rule was used to find each number in column B. Rule: Multiply the number in Column A by itself and then add 3. Find the missing number, using the same rule. A 2 3 5 8 6) B 7 12 28 ? Which number is both a factor of 100 and a multiple of 5? A. 4 B. 40 C. 50 D. 80 3 Mathematics Grade 4 – Unit 1 (SAMPLE) 7) Peter made the statement below. “The number 32 is a multiple of 8. That means all of the factors of 8 are also factors of 32.” Is Peter’s statement correct? Why? 8) Draw a model to show the factor pairs of 18. Is 18 a prime number or a composite number? How do you know? 9) Draw a model to show the factor pairs of 5. Is 5 a prime number or a composite number? How do you know? 10) Randi bought some tickets to win a bicycle. The tickets are listed below. The winning ticket number was described as being a multiple of 2 and having the most factors. What was the winning ticket number? How many factors are there? Explain your reasoning. 18 48 17 64 4 Mathematics Grade 4 – Unit 1 (SAMPLE) Sample End of Unit Assessment Task: I. The two-eyed space creatures, three-eyed space creatures, and four-eyed space creatures are having a contest to create a group with 24 total eyes. a. How many two-eyed creatures are needed to make a group with 24 total eyes? How many three-eyed creatures needed to make a group of 24 total eyes? How many foureyed creatures are needed to make a group with 24 total eyes? Complete the chart below. Creature Groups Two-eyed Three-eyed Four-eyed Groups Made b. The creatures decided to have a contest to create a group with 40 total eyes. Only groups that can form a group of with 40 eyes can participate. Can all three groups listed in part a participate in this contest? Tell how you know. c. If other creature groups decided to join in the contest with the 40 total eyes, which of the following creature groups could participate: one-eyed creatures, five-eyed creatures, seven-eyed creatures, or eight-eyed creatures? Explain your thinking. d. The three-eyed creatures tell the six-eyed creatures that they cannot participate in the contest in part c. Is this true? Why, or why not? Please explain your thinking. Adapted from: “The Contest” Item #43081-43804 http://sampleitems.smarterbalanced.org/itempreview/sbac/index.htm 5 Mathematics Grade 4 – Unit 1 (SAMPLE) II. The table below shows a list of numbers. For every number listed in the table, multiply it by 2 then add 1. a. Record the results of your calculations in the right column of the table. Number 0 1 2 3 4 5 10 Multiply by 2 then add one b. What do you notice about the numbers you entered into the table? c. Sherri decided to apply the rule, multiply by 2, and add 1, to the numbers 6—9. Below is the table she created. Sherri noticed that all the numbers she entered are odd. Explain why all of the numbers are odd. Number 6 7 8 9 Double the number plus one 13 15 17 21 Adapted from: http://www.illustrativemathematics.org/illustrations/487 6 Mathematics Grade 4 – Unit 1 (SAMPLE) Sample End-of-unit Assessment Item Responses: 1) What factor of 12 is missing in the list of numbers? (4.OA.C.5) Solution: 6 1, 2, 3, 4, _6_, 12 2) On the chart, circle all the numbers that have 4 as a factor. (4.OA.B.4) 3) 4) 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Which of these numbers is a prime number? (4.OA.B.4) Solution: C, 67 A. 6 B. 27 C. 67 D. 81 The pattern below is found by adding 5 to the first term to get the second term. Then subtract 2 from the second term to get the third term. The pattern of adding 5, then subtracting 2 to get the next two terms continues. Write the next two numbers in the number pattern. (4.OA.C.5) 1 6 4 9 7 12 10 __15__ __13___ Explain why after the first term of 1, the pattern alternates with 2 evens then 2 odds. Solution: The pattern alternates with two evens and two odds because subtracting two even numbers will always be even, subtracting odd and even numbers will always be odd, adding two odds will always be even, and adding an even and an odd number will always be odd. Therefore, adding 5 to 1, an odd number, results in an even number. Then subtracting 2 will result in another even number. Next adding 5 to the even number will result in an odd number. Since subtracting 2 from an odd number will result in another odd number, the next number in the pattern is odd. This pattern of two evens followed by two odd numbers will continue after the number 1. 5) The table below shows some number pairs. The following rule was used to find each number in column B. (4.OA.C.5) Rule: Multiply the number in Column A by itself and then add 3. Find the missing number, using the same rule. Solution: 67 A B 2 7 3 12 5 28 8 67 7 Mathematics Grade 4 – Unit 1 (SAMPLE) 6) 7) Which number is both a factor of 100 and a multiple of 5? (4.OA.B.4) Solution: C, 50 A. 4 B. 40 C. 50 D. 500 Peter made the statement below. (4.OA.B.4) “The number 32 is a multiple of 8. That means all of the factors of 8 are also factors of 32.” Is Peter’s statement correct? Why or Why not? Solution: Yes, his statement is correct. The factors of 8 are 1, 2, 4, and 8. 32 = 8 x 4 and 8 = 2 x 4 that means 32 = (2 x 4) x 4. Also, 1 is a factor of all numbers. So, all factors of 8 are also factors of 32. Students might also say “The factors of 8 are 1, 2, 4, and 8. 1, 2, 4, and 8 all divide 32 without a remainder, so they are all factors of 32.” This is also an acceptable response. 8) Draw a model to show the factor pairs of 18. Is 18 a prime number or a composite number? How do you know? (4.OA.B.4) Solution: Students should include models to show the following factor pairs (1x18, 2x9, and 3x6) 18 is a composite number because 18 has more than one factor pair. Students do not need to provide all six models below—one model for each factor pair should be included. 9) Draw a model to show the factor pairs of 5. Is 5 a prime number or a composite number? How do you know? (4.OA.B.4) Solution: Students should only show the model of 5x1. 5 is a prime number because 5 has exactly two factors, or one factor pair, one and itself. Students only need to show one of the models below. 8 Mathematics Grade 4 – Unit 1 (SAMPLE) 10) Randi bought some tickets to win a bicycle. The tickets are listed below. The winning ticket number was described as being a multiple of 2 and having the most factors. What was the winning ticket number? How many factors are there? Explain your reasoning. (4.OA.B.4) Solution: Even numbers are multiples of two. Therefore, the ticket numbers that are multiples of 2 are 18, 48, and 64. Ticket number 18 has factors as follows: 1, 2, 3, 6, 9, and 18. Ticket number 48 has factors as follows: 1, 2, 3, 4, 6, 8, 12, 16, 24, and 48. Ticket number 64 has factors as follows: 1, 2, 4, 8, 16, 32 and 64. The winning ticket number is 48. Ticket 48 is a multiple of 2 and ticket number 48 has the most factors which is 10 factors. 18 48 17 64 9 Mathematics Grade 4 – Unit 1 (SAMPLE) Sample End of Unit Assessment Task Response: (4.OA.B.4) I. The two-eyed space creatures, three-eyed space creatures, and four-eyed space creatures are having a contest to create a group with 24 total eyes. a. How many two-eyed creatures are needed to make a group with 24 total eyes? How many three-eyed creatures needed to make a group of 24 total eyes? How many foureyed creatures are needed to make a group with 24 total eyes? Complete the chart below. Creature Groups Two-eyed Three-eyed Four-eyed Groups Made 12 8 6 b. The creatures decided to have a contest to create a group with 40 total eyes. Only groups that can form a group of with 40 eyes can participate. Can all three groups listed in part a participate in this contest? Tell how you know. Solution: No, the three-eyed creatures could not have a group to make a group with 40 total eyes. Three-eyed groups would only be multiples of 3 (for example, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, etc…). They could have a group with a total of 39 or 42. c. If other creature groups decided to join in the contest with the 40 total eyes, which of the following creature groups could participate: one-eyed creatures, five-eyed creatures, seven-eyed creatures, or eight-eyed creatures? Explain your thinking. Solution: The one-eyed, five-eyed and eight-eyed can participate because they are factors of 40. The seven-eyed could not participate because 7 is not a factor of 40. d. The three-eyed creatures tell the six-eyed creatures that they cannot participate in the contest in part c. Is this true? Why, or why not? Please explain your thinking. Solution: Yes, it is true. The six-eyed groups would only be multiples of 6 (for example, 6, 12, 18, 24, 30, 36, 42, etc…). They could have a group with a total of 36 or 42. 10 Mathematics Grade 4 – Unit 1 (SAMPLE) II. The table below shows a list of numbers. For every number listed in the table, multiply it by 2 then add 1. (4.OA.B.4) a. Record the results of your calculations in the right column of the table. Number 0 1 2 3 4 5 10 Multiply by 2 then add one 1 3 5 7 9 11 21 b. What do you notice about the numbers you entered into the table? Solution: There are several patterns that students might see. For example, they might notice that the result increases by two when the number increases by one. Hopefully, some students will notice that all the numbers they entered are odd. c. Sherri decided to apply the rule, multiply by 2, and add 1, to the numbers 6—9. Below is the table she created. Sherri noticed that all the numbers she entered are odd. Explain why all of the numbers are odd. Solution: The values in the right column are all odd because multiplying an even or an odd number by 2 always results in an even number. An even number plus 1 will always result in an add number. Number 6 7 8 9 Double the number plus one 13 15 17 21 11 Mathematics Grade 4 – Unit 1 (SAMPLE) Possible Pacing and Sequence of Standards Content and Practice Standards Gain familiarity with factors and multiples. 4.OA.B.4 Find all factor pairs for a whole number in the range 1-100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1-100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1-100 is prime or composite. Generate and analyze patterns. 4.OA.C.5 Generate a number or shape pattern that follows a given rule. Identify apparent features of the pattern that were not explicit in the rule itself. For example, given the rule, “Add 3” and the starting number 1, generate terms in the resulting sequence and observe that the terms appear to alternate between odd and even numbers. Explain informally why the numbers will continue to alternate in this way. Possible Connections to Standards for Mathematical Practices MP.1 Make sense of problems and persevere in solving them. Students will need to make sense of the application task and persevere to determine how many hot dogs and hot dog buns to buy to feed a given number of Possible Pacing and Sequence Days 1-5 Objectives: Students will list all of the factor pairs for any whole number in the range 1—100. Students will determine multiples of a given whole number (1—100). Students will investigate to determine if a number is prime or composite. Concepts and Skills: • Understand the terms “factors” and “multiples.” • Find factors of a given whole number using different strategies (making rectangles with colored tiles or grid paper, and number charts). • Use different strategies to show and explain why a number is prime or composite • Understand that 1 is neither prime nor composite. • Use skip counting by factors to determine multiples. • Explain whether a given whole number is a multiple of a given one-digit number. Sample Tasks: 1) Use the list of numbers below to answer the questions. 8, 9, 19, 27, 31, 33, 56 a. Which numbers are multiples of 2? Show how you know. b. Which numbers are multiples of 3? Show how you know. c. Which numbers are multiples of 5? Show how you know. 2) Use models to show all factor pairs for 47. Is this number prime or composite? How do you know? 12 Mathematics Grade 4 – Unit 1 (SAMPLE) people. Students continually evaluate their reasoning by asking, “Does this make sense?” MP.2 Reason abstractly and quantitatively. In order for students to determine whether answers are reasonable, students have to think about their answer in the given context which requires quantitative reasoning. Day 6 Objectives: Students apply the understandings of factors and multiples to solve a real-world problem. Application Task Description: This task uses student understandings of multiples to determine how much will need to be purchased for a class picnic. While some of the problems may seem like students are asked to find the least common multiple (LCM) or greatest common factor (GCF), these skills are not required and should not be taught at this time. Those concepts are reserved for grade 6. Days 7-8 Objectives: Students will generate a pattern that follows a given rule. MP.3 Construct viable arguments and critique the reasoning of others. Students will make logical arguments and respond to the mathematical thinking of others when discussing their work. Students may use objects or drawings to Students will identify and explain additional patterns or special behaviors in a pattern that go beyond the construct arguments while critiquing the reasoning given rule. of others. Concepts and Skills: MP.4 Model with mathematics. • Create and extend number patterns that repeat or grow. Students will represent factor pairs in various ways • Explain why other patterns that are not stated in the given rule (i.e., why all resulting numbers including building rectangular arrays. are even, all numbers are odd, numbers alternate even/odd, etc…) occur. MP.6 Attend to precision. Students will attend to precision in the vocabulary they use in their explanations. They will also attend to precision when finding all factor pairs for a given number. MP.7 Look for and make use of structure. Students will look closely to discern patterns or structures. Students will make sense of structure when finding multiples and factors of a given number. Sample Tasks: 1) There are 3 candies in the jar. Each day 2 candies are added. How many candies are in the jar on the 5th day? After completing the table, look at the numbers in the Candies column. Find at least one pattern you see that is not a part of the rule? Explain the pattern in terms of how the number of candies changes. Day Calculation Candies 0 2x0+3 3 1 2x1+3 5 2 2x2+3 7 3 2x3+3 9 4 5 13 Mathematics Grade 4 – Unit 1 (SAMPLE) MP.8 Look for and express regularity in repeated reasoning. Students will look for and express regularity in repeated reasoning when finding the next number when given a rule. Students may notice if calculations are repeated and look for both general methods and shortcuts. 2) Use the rule multiply by 3, subtract 1 to write the numbers in the pattern. What do you observe about the numbers in the pattern? Explain your observations. 2, _____, ______, ______, _____ Days : End of Unit Assessment 9-10 14 Mathematics Grade 4 – Unit 1 (SAMPLE) Application Task: Teacher Note: The following problem is often used to find the least common multiple or greatest common factor. Understanding least common multiple or greatest common factor is not a requirement of 4th grade students as the skill/concept is left for Grade 6. Students can complete these problems by applying their understanding of multiples without understanding the concept of LCM or GCF. Isaac is planning a picnic for his classmates. Everyone coming to the picnic wants to eat hot dogs. He knows that hot dogs at the local store are sold 10 in a package. The hot dogs buns are sold 8 in a package. 1. What is the least number of packages of hot dogs and hot dog buns Isaac can buy to have exactly the same amount of hot dogs and buns? Show how you determined your answer. 2. Isaac discovers that 30 people are coming to the picnic and everyone wants to eat 2 hot dogs! What is the least number of packages of hot dogs Isaac will have to buy to feed all 30 people? What is the least number of packages of buns Isaac will have to buy to feed all 30 people? Show how you know. Total number of hot dogs and buns needed Number in package Total packages needed Hot dogs Hot dog buns 3. Isaac noticed he would have more hot dog buns than hot dogs. He decided not to waste food so he wanted to feed the teachers in the other grades. a. What is the least number of packages of hot dogs and hot dog buns will Isaac need to buy to have exactly the same number of hot dogs and buns to feed all 30 people two hot dogs each? Tell how you know. b. How many extra hot dogs will there be to feed the teachers in the other grades? Explain how you know. c. If each teacher in the other grades eats two hot hogs, how many teachers can eat? Explain your reasoning. 4. Isaac asked some of the students in other classes to bring some other items for the picnic. Help Isaac’s friends figure out what they need to buy. a. Tanya will bring the ketchup. She already has 3 bottles and each bottle has enough for 20 hot dogs. How many more bottles of ketchup will Tanya need to buy for there to be enough ketchup for all of the hot dogs? Show how you found your answer. 15 Mathematics Grade 4 – Unit 1 (SAMPLE) b. Jordan found boxes of mustard packets. One box has 10 mustard packets. How many packs of mustard must Jordan buy to have enough mustard for all of the hot dogs, if one packet is used for each hot dog? Show how you found your answer. 16 Mathematics Grade 4 – Unit 1 (SAMPLE) Application Task: Isaac is planning a picnic for his classmates. Everyone coming to the picnic wants to eat hot dogs. He knows that hot dogs at the local store are sold 10 in a package. The hot dogs buns are sold 8 in a package. 1. What is the least number of packages of hot dogs and hot dog buns Isaac can buy to have exactly the same amount of hot dogs and buns? Show how you determined your answer. Solution: hot dog packages hot dog bun packages Isaac would need to buy 4 packages of hot dogs and 5 packages of hot dog buns to have the exactly the same number of hot dogs and hot dog buns. Count by multiples of 10 and multiples of 8. 2. Isaac discovers that 30 people are coming to the picnic and everyone wants to eat 2 hot dogs! What is the least number of packages of hot dogs Isaac will have to buy to feed all 30 people? What is the least number of packages of buns Isaac will have to buy to feed all 30 people? Show how you know. Hot dogs Hot dog buns Total number of hot dogs and buns needed 30 people x 2 hot dogs = 60 hot dogs 30 people x 2 hot dogs = 60 hot dog buns Number in package 10 in package 8 in package Total packages needed 6 packages of hot dogs x 10 = 60 hot dogs 8 packages of hot dog buns x 8 = 64 hot dog buns 7 packages would only be 56 buns (7 x 8) which is not enough. 3. Isaac noticed he would have more hot dog buns than hot dogs. He decided not to waste food so he wanted to feed the teachers in the other grades. a. What is the least number of packages of hot dogs and hot dog buns will Isaac need to buy to have exactly the same number of hot dogs and buns and still be able to feed all 30 people two hot dogs each? Tell how you know. Solution: 30 x 2 = 60 hot dogs will be needed to feed all 30 people. hot dog packages hot dog bun packages Since Isaac will need 60 hot dogs, he will need to buy 8 packages of hot dogs and 10 packages of hot dog buns to have exactly the same number of hot dogs and hot dog buns. 17 Mathematics Grade 4 – Unit 1 (SAMPLE) b. How many extra hot dogs will there be to feed the teachers in the other grades? Explain how you know. Solution: 80 total hot dogs will be made. 60 of them will be used to feed the other people. So, there will be 20 hot dogs left to feed the teachers in the other grades. c. If each teacher in the other grades eats two hot hogs, how many teachers can eat? Explain your reasoning. Solution: There will be 20 hot dogs left over. If each teacher eats two hot dogs, then 10 teachers can eat. 4. Isaac asked some of the students in other classes to bring some other items for the picnic. Help Isaac’s friends figure out what they need to buy. a. Tanya will bring the ketchup. She already has 3 bottles and each bottle has enough for 20 hot dogs. How many more bottles of ketchup will Tanya need to buy for there to be enough ketchup for all of the hot dogs? Show how you found your answer. Solution: 3 bottles x 20 servings = 60 servings total 80 servings needed – 60 servings = 20 more servings needed 1 bottle has 20 servings so Tanya needs to buy 1 more bottle of ketchup. b. Jordan found boxes of mustard packets. One box has 10 mustard packets. How many packs of mustard must Jordan buy to have enough mustard for all of the hot dogs, if one packet is used for each hot dog? Show how you found your answer. Solution: 80 packets are needed. 16 boxes x 5 packets = 80 packets. So Jordan needs to buy 16 boxes of mustard packets. 18