CorrectionKey A Factors And Multiples MODULE 2

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Factors andMultiples?MODULE2LESSON 2.1ESSENTIAL QUESTIONGreatest CommonFactorHow can you use greatestcommon factors and leastcommon multiples to solvereal-world problems?6.NS.4LESSON 2.2Least CommonMultiple Houghton Mifflin Harcourt Publishing Company Image Credits: STOCK4B-RF/Getty Images6.NS.4Real-World VideoOrganizers of banquets and other special eventsplan many things, including menus, seatingarrangements, table decorations, and party favors.my.hrw.com Factors and multiples can be helpful in this work.my.hrw.commy.hrw.comMath On the SpotAnimated MathPersonal Math TrainerGo digital with yourwrite-in studentedition, accessible onany device.Scan with your smartphone to jump directlyto the online edition,video tutor, and more.Interactively explorekey concepts to seehow math works.Get immediatefeedback and help asyou work throughpractice sets.27

Are YOU Ready?PersonalMath TrainerComplete these exercises to review skills you will needfor this module.Multiplesmy.hrw.com5 1 5EXAMPLE5 2 105 3 155 4 205 5 25Online Practiceand HelpTo find the firstfive multiples of 5,multiply 5 by 1, 2, 3,4, and 5.List the first five multiples of the number.1. 72. 113. 15Factors1 12 122 6 123 4 12The factors of 12 are 1, 2, 3, 4, 6, 12.EXAMPLETo find the factors of 12, usemultiplication facts of 12.Continue until pairs offactors repeat.Write all the factors of the number.4. 245. 366. 457. 32Multiplication Properties (Distributive)To multiply a number by a sum,multiply the number by each addendand add the products.Use the Distributive Property to find the product.8. 8 15 8 28Unit 1( ( ) () )9. 6 17 6 ( ( ) () ) Houghton Mifflin Harcourt Publishing Company7 14 7 (10 4) (7 10) (7 4) 70 28 98EXAMPLE

Reading Start-UpVocabularyReview WordsVisualize Vocabulary area (área) Distributive Property(Propiedad distributiva) factor (factor) multiple (múltiplo) product (producto)Use the words to complete the graphic.3 (4 5) 3 4 3 56 6 36Preview Wordsgreatest common factor(GCF) (máximo comúndivisor (MCD))least common multiple(LCM) (mínimo comúnmúltiplo (m.c.m.))MultiplyingWholeNumbers9: 18, 27, 36, 45, 54, 6312: 24, 36, 48, 60, 72, 849: 1, 3, 912: 1, 2, 3, 4, 6, 12Understand VocabularyComplete the sentences below using the preview words.1. Of all the whole numbers that divide evenly into two ormore numbers, the one with the highest value is calledthe.2. Of all the common products of two numbers, the one with the lowest Houghton Mifflin Harcourt Publishing Companyvalue is called the.Active ReadingTwo-Panel Flip Chart Create a two-panel flipchart to help you understand the concepts inthis module. Label one flap “Greatest CommonFactor.” Label the other flap “Least CommonMultiple.” As you study each lesson, writeimportant ideas under the appropriate flap.Module 229

GETTING READY FORFactors and MultiplesUnderstanding the standards and the vocabulary terms in the standardswill help you know exactly what you are expected to learn in this module.Find the greatest commonfactor of two whole numbersless than or equal to 100 andthe least common multiple oftwo whole numbers less than orequal to 12. Use the DistributiveProperty to express a sum oftwo whole numbers 1–100 witha common factor as a multipleof a sum of two whole numberswith no common factor.Key Vocabularygreatest common factor (GCF)(máximo común divisor (MCD))The largest common factor oftwo or more given numbers.6.NS.4Find the greatest commonfactor of two whole numbersless than or equal to 100 andthe least common multiple oftwo whole numbers less than orequal to 12.Key Vocabularyleast common multiple (LCM)(mínimo común múltiplo (m.c.m.))The smallest number, otherthan zero, that is a multiple oftwo or more given numbers.What It Means to YouYou will determine the greatest common factor of two numbersand solve real-world problems involving the greatest commonfactor.EXAMPLE 6.NS.4There are 12 boys and 18 girls in Ms. Ruiz’s science class. Each labgroup must have the same number of boys and the same numberof girls. What is the greatest number of groups Ms. Ruiz can make ifevery student must be in a group?Factors of 12: 1, 2, 3, 4, 6, 12Factors of 18: 1, 2, 3, 6, 9, 18The GCF of 12 and 18 is 6. The greatest number of groups Ms. Ruizcan make is 6.What It Means to YouYou will determine the least common multiple of two numbers andsolve real-world problems involving the least common multiple.EXAMPLE 6.NS.4Lydia’s family will provide juice boxesand granola bars for 24 players.Juice comes in packs of 6, andgranola bars in packs of 8. What isthe least number of packs of eachneeded so that every player has a drink anda granola bar and there are none left over?Multiples of 6: 6, 12, 18, 24, 30, Visit my.hrw.comto see all CACommon CoreStandardsexplained.my.hrw.com30Unit 1Multiples of 8: 8, 16, 24, 32, The LCM of 6 and 8 is 24. Lydia’s family should buy 24 6 4packs of juice and 24 8 3 packs of granola bars. Houghton Mifflin Harcourt Publishing Company Image Credits: Andy Dean Photography/Shutterstock.com6.NS.4

LESSON2.1?Greatest CommonFactorESSENTIAL QUESTION6.NS.4Find the greatest common factor of two wholenumbers less than or equal to 100 and the leastcommon multiple of two whole numbers lessthan or equal to 12. Use the distributive propertyto express a sum of two whole numbers 1–100with a common factor as a multiple of a sum oftwo whole numbers with no common factor.How can you find and use the greatest common factor of twowhole numbers?EXPLORE ACTIVITY 16.NS.4Understanding Common FactorsThe greatest common factor (GCF) of two numbers is the greatestfactor shared by those numbers.A florist makes bouquets from 18 roses and 30 tulips. All thebouquets include both roses and tulips. All bouquets areidentical, and all the flowers are used. You can make tablesto see the possible ways the florists can make the bouquets.A Complete the tables to show the possible ways to divide eachtype of flower among the bouquets.What are the possible ways the florist can make bouquets of roses?Number of Bouquets12Number of Roses in Each Bouquet18936918 Houghton Mifflin Harcourt Publishing CompanyWhat are the possible ways the florist can make bouquets of tulips?Number of Bouquets1Number of Tulips in Each Bouquet302356101530B Can the florist make five bouquets using all the flowers? Explain.C What are the common factors of 18 and 30? What do they represent?D What is the GCF of 18 and 30?Reflect1.What If? Suppose the florist has 18 roses and 36 tulips. What is the GCF of thenumbers of roses and tulips? Explain.Lesson 2.131

Finding the Greatest Common FactorOne way to find the GCF of two numbers is to list all of their factors. Then youcan identify common factors and the GCF.Math On the Spotmy.hrw.comMy NotesEXAMPLE 16.NS.4A baker has 24 sesame bagels and 36 plainbagels to put into boxes. Each box must havethe same number of each type of bagel.What is the greatest number of boxes that thebaker can make using all of the bagels? Howmany sesame bagels and how many plainbagels will be in each box?STEP 1STEP 2The baker can divide24 sesame bagels into groupsof 1, 2, 3, 4, 6, 8, 12, or 24.List the factors of 24 and 36.Then circle the common factors.Factors of 24:1234681224Factors of 36:123469121836Find the GCF of 24 and 36.The GCF is 12. So, the greatest number of boxes that the bakercan make is 12. There will be 2 sesame bagels in each box, because24 12 2. There will be 3 plain bagels, because 36 12 3.ReflectCritical Thinking What is the GCF of two prime numbers? Give an example.YOUR TURNFind the GCF of each pair of numbers.3. 14 and 35PersonalMath TrainerOnline Practiceand Helpmy.hrw.com32Unit 14. 20 and 285. The sixth-grade class is competing in the school field day. There are 32 girls and40 boys who want to participate. Each team must have the same number of girlsand the same number of boys. What is the greatest number of teams that can beformed? How many boys and how many girls will be on each team? Houghton Mifflin Harcourt Publishing Company2.

EXPLORE ACTIVITY 26.NS.4Using the Distributive PropertyYou can use the Distributive Property to rewrite a sum of two or more numbersas a product of their GCF and a sum of numbers with no common factor otherthan 1. To understand how, you can use grid paper to draw area models of 45and 60. Here are all the possible area models of 45.1AnimatedMathmy.hrw.com4535159A What do the side lengths of the area models (1, 3, 5, 9, 15, and 45)represent?B On your own grid paper, show all of the possible area models of 60.C What side lengths do the area models of 45 and 60 have in common?What do the side lengths represent?D What is the greatest common side length? What does it represent?E Write 45 as a product of the GCF and another number.Write 60 as a product of the GCF and another number. Houghton Mifflin Harcourt Publishing CompanyF Use your answers above to rewrite 45 60.45 60 15 15 Use the Distributive Property and your answer above to write45 60 as a product of the GCF and a sum of two numbers.15 15 15 ( ) 15 7Math TalkMathematical PracticesHow can you checkto see if your product iscorrect?ReflectWrite the sum of the numbers as the product of their GCF and another sum.6. 27 187. 120 368. 9 35Lesson 2.133

Guided Practice1. Lee is sewing vests using 16 green buttons and 24 blue buttons. All thevests are identical, and all have both green and blue buttons. What are thepossible numbers of vests Lee can make? What is the greatest number ofvests Lee can make? (Explore Activity 1, Example 1)List the factors of 16 and 24. Then circle the common factors.Factors of 16:Factors of 24:What are the common factors of 16 and 24?What are the possible numbers of vests Lee can make?What is the GCF of 16 and 24?What is the greatest number of vests Lee can make?Write the sum of numbers as a product of their GCF and another sum.(Explore Activity 2)2. 36 45What is the GCF of 36 and 45?Write each number as a product of the GCF and another number.Then use the Distributive Property to rewrite the sum.( ) ( ) ( )( )3. 75 90Write each number as a product of the GCF and another number.Then use the Distributive Property to rewrite the sum.(? ) ( ) ( ) ( )ESSENTIAL QUESTION CHECK-IN4. Suppose you write a sum of numbers as a product of their GCF andanother sum. What is the GCF of the numbers in the other sum? Explain.34Unit 1 Houghton Mifflin Harcourt Publishing CompanyWhat is the GCF of 75 and 90?

NameClassDate2.1 Independent PracticePersonalMath Trainer6.NS.4my.hrw.comOnline Practiceand HelpList the factors of each number.5. 126. 507. 398. 64Find the GCF of each pair of numbers.9. 40 and 4810. 30 and 4511. 10 and 4512. 25 and 9013. 21 and 4014. 28 and 7015. 60 and 7216. 45 and 8117. 28 and 3218. 55 and 77 Houghton Mifflin Harcourt Publishing Company Image Credits: Photodisc/Getty Images19. Carlos is arranging books on shelves. He has 32 novels and 24autobiographies. Each shelf will have the same numbers of novelsand autobiographies. If Carlos must place all of the books on shelves,what are the possible numbers of shelves Carlos will use?20. The middle school band has 56 members. The high school band has 96members. The bands are going to march one after the other in a parade.The director wants to arrange the bands into the same number ofcolumns. What is the greatest number of columns in which the two bandscan be arranged if each column has the same number of marchers? Howmany marchers will be in each column?21. For football tryouts at a local school, 12 coaches and 42 players will splitinto groups. Each group will have the same numbers of coaches andplayers. What is the greatest number of groups that can be formed? Howmany coaches and players will be in each of these groups?22. Lola is placing appetizers on plates. She has 63 spring rolls and 84 cheesecubes. She wants to include both appetizers on each plate. Each platemust have the same numbers of spring rolls and cheese cubes. What is thegreatest number of plates she can make using all of the appetizers? Howmany of each type of appetizer will be on each of these plates?Lesson 2.135

Write the sum of the numbers as the product of their GCF and another sum.23. 56 6424. 48 1425. 30 5426. 24 4027. 55 6628. 49 6329. 40 2530. 63 1531. Explain why the greatest common factor of two numbers is sometimes 1.FOCUS ON HIGHER ORDER THINKINGWork Area32. Communicate Mathematical Ideas Tasha believes that she can rewritethe difference 120 - 36 as a product of the GCF of the two numbers andanother difference. Is she correct? Explain your answer.34. Critique Reasoning Xiao’s teacher asked him to rewrite the sum60 90 as the product of the GCF of the two numbers and a sum.Xiao wrote 3(20 30). What mistake did Xiao make? How shouldhe have written the sum?36Unit 1 Houghton Mifflin Harcourt Publishing Company33. Persevere in Problem Solving Explain how to find the greatest commonfactor of three numbers.

LESSON2.2?Least CommonMultipleESSENTIAL QUESTION6.NS.4Find the greatest common factor of two wholenumbers less than or equal to 100 and the leastcommon multiple of two whole numbers less thanor equal to 12. Use the distributive property toexpress a sum of two whole numbers 1–100 with acommon factor as a multiple of a sum of two wholenumbers with no common factor.How do you find and use the least common multipleof two numbers?6.NS.4EXPLORE ACTIVITYFinding the Least Common MultipleA multiple of a number is the product of the number and anothernumber. For example, 9 is a multiple of the number 3. The leastcommon multiple (LCM) of two or more numbers is the leastnumber, other than zero, that is a multiple of all the numbers.Ned is training for a biathlon. He will swim every sixth day andbicycle every eighth day. On what days will he both swimand bicycle? Houghton Mifflin Harcourt Publishing Company Image Credits: Murray Richards/Icon SMI/CorbisA In the chart below, shade each day that Ned will swim.Circle each day Ned will B On what days will Ned both swim and bicycle?The numbers of the days that Ned will swim and bicycle arecommon multiples of 6 and 8.Reflect1.Communicate Mathematical Ideas What does the LCM represent inthis situation?Lesson 2.237

Applying the LCMYou can use the LCM of two whole numbers to solve problems.EXAMPLE 1Math On the Spotmy.hrw.com6.NS.4A store is holding a promotion. Every third customer receives a free keychain, and every fourth customer receives a free magnet. Which customerwill be the first to receive both a key chain and a magnet?STEP 1STEP 2Math TalkMathematical PracticesList the multiples of 3 and 4. Then circle the common multiples.Multiples of 3: 369121518212427Multiples of 4: 4812162024283236Find the LCM of 3 and 4.The LCM is 12.What steps do you take tolist multiples of anumber?The first customer to get both a key chain and a magnet is the12th customer.YOUR TURN2. Find the LCM of 4 and 9 by listing the multiples.PersonalMath TrainerMultiples of 4:Online Practiceand HelpMultiples of 9:my.hrw.com1. After every ninth visit to a restaurant you receive a free beverage. Afterevery twelfth visit you receive a free appetizer. If you visit the restaurant100 times, on which visits will you receive a free beverage and a freeappetizer? At which visit will you first receive a free beverage and a freeappetizer? (Explore Activity 1, Example 1)?ESSENTIAL QUESTION CHECK-IN2. Do two whole numbers always have a least common multiple? Explain.38Unit 1 Houghton Mifflin Harcourt Publishing CompanyGuided Practice

NameClassDate2.2 Independent PracticePersonalMath Trainer6.NS.4my.hrw.comOnline Practiceand HelpFind the LCM of each pair of numbers.3. 8 and 564. 25 and 505. 12 and 306. 6 and 107. 16 and 248. 14 and 219. 9 and 1510. 5 and 1111. During February, Kevin will water his ivy every third day, and water hiscactus every fifth day.a. On which date will Kevin first water both plants together?b. Will Kevin water both plants together again in February? Explain. Houghton Mifflin Harcourt Publishing Company Image Credits: Eric Nathan/Alamy12. Vocabulary Given any two numbers, which is greater, the LCM of thenumbers or the GCF of the numbers? Why?Use the subway train schedule.13. The red line and the blue line trains just arrived at the station.When will they next arrive at the station at the same time?Inminutes14. The blue line and the yellow line trains just arrived at the station.When will they next arrive at the station at the same time?Train ScheduleInminutes15. All three trains just arrived at the station. When will they nextall arrive at the station at the same time?InminutesTrainArrives Every Red line8 minutesBlue line10 minutesYellow line12 minutesLesson 2.239

16. You buy a lily and an African violet on the same day. You are instructedto water the lily every fourth day and water the violet every seventh dayafter taking them home. What is the first day on which you will waterboth plants on the same day? How can you use this answer to determineeach of the next days you will water both plants on the same day?FOCUS ON HIGHER ORDER THINKINGWork Area17. What is the LCM of two numbers if one number is a multiple of the other?Give an example.18. What is the LCM of two numbers that have no common factors greaterthan 1? Give an example.20. Communicate Mathematical Ideas Describe how to find the leastcommon multiple of three numbers. Give an example.40Unit 1 Houghton Mifflin Harcourt Publishing Company19. Draw Conclusions The least common multiple of two numbers is 60,and one of the numbers is 7 less than the other number. What are thenumbers? Justify your answer.

MODULE QUIZReadyPersonalMath Trainer2.1 Greatest Common FactorOnline Practiceand HelpFind the GCF of each pair of numbers.my.hrw.com1. 20 and 322. 24 and 563. 36 and 904. 45 and 755. 28 girls and 32 boys volunteer to plant trees at a school.The principal divides the girls and boys into groups thathave girls and boys in each group. What is the greatestnumber of groups the principal can make?Write the sum of the numbers as the product of their GCF and another sum.6. 32 207. 18 272.2 Least Common MultipleFind the LCM of each pair of numbers.8. 6 and 1210. 8 and 99. 6 and 1011. 9 and 1212. Juanita runs every third day and swims every fifth day.If Juanita runs and swims today, in how many dayswill she run and swim again on the same day? Houghton Mifflin Harcourt Publishing CompanyESSENTIAL QUESTION13. What types of problems can be solved using the greatest commonfactor? What types of problems can be solved using the leastcommon multiple?Module 241

MODULE 2MIXED REVIEWPersonalMath TrainerAssessment Readinessmy.hrw.comOnline Practiceand Help1. A sporting goods store gave a free T-shirt to every 8th customer and a freewater bottle to every 10th customer for a promotional event.Select Yes or No if the customer would receive both a free T-shirt and a freewater bottle.A. the 20th customerB. the 40th customerC. the 160th customerYesYesYesNoNoNo2. Laura found the greatest common factor of several pairs of numbers.Choose True or False for each statement.A. The greatest common factor of 24 and 18 is 6.B. The greatest common factor of 24 and 48 is 48.C. The greatest common factor of 96 and 56 is 4.TrueTrueTrueFalseFalseFalse4. Tia is buying paper cups and plates. Cups come in packages of 12, and platescome in packages of 10. She wants to buy the same number of cups andplates, but she wants to buy the least number of packages possible. Howmuch should Tia expect to pay if each package of cups costs 3 and eachpackage of plates costs 5? Explain.42Unit 1 Houghton Mifflin Harcourt Publishing Company3. A diver plans to visit three reefs in the Pacific Ocean. Reef A has an elevationof -27 meters, and Reef B has an elevation of -31 meters. Martina says ReefA is deeper than Reef B because -27 -31. Is Martina correct? Explain yourreasoning.

Personal Math Trainer Interactively explore key concepts to see how math works. Animated Math Go digital with your write-in student edition, accessible on any device. Scan with your smart phone to jump dire