Thank you for participating in Teach It First! This Teach It First Kit contains a Common Core Support Coach, Foundational Mathematics teacher lesson followed by the corresponding student lesson. We are confident that using this lesson will help you achieve your assessment preparation goals for your entire class. Common Core Support Coach was built from the ground-up to provide students with scaffolded support for content required by the Common Core State Standards for Mathematics (CCSS-M). The program features 20 lessons which focus on 20 critical skills essential to mastery of Common Core State Standards. These skills were chosen because they are critical components of the mathematical progressions that connect earlier standards to this grade level and from this grade level to the next. While each lesson connects to prior foundational skills and concepts, it can be viewed as an independent unit of instruction. In this way, the 20 lessons allow teachers to differentiate instruction according to the requirements of each student. Key to the philosophy behind Common Core Support Coach is the recognition that math skills and concepts are part of a progression that begins early in students’ lives and continues beyond their current grade level with increased complexity and depth. For students, achieving true understanding of CCSS-M at any grade level means mastery of prior content that connects to this grade and mastery of content that connects within the grade. Often, students who cannot cope with a specific part of their grade’s curriculum are missing one or more understandings that would allow mastery. Common Core Support Coach supplies the missing pieces. We are happy to provide you this complimentary sample and would love to know what you think. Once you have read through this lesson, do what you do best— present it to your students. Then, don’t forget to complete a quick survey by going to www.triumphlearning.com/teach-it-first/survey. By doing so, you will be entered into our quarterly raffle for one of five American Express $100 gift cards. Regards, Triumph Learning Join the conversation about Common Core today by visiting commoncore.com, the place where teachers, parents, and experts come together to share best practices and practical information for successfully implementing Common Core standards in the classroom. 136 Madison Avenue • New York, NY 10016 • p: 212.652.0215 • f : 212.857.8499 • www.triumphlearning.com LESSON 14 S uppor tCoa c h, Ma t he ma t i c s , T e a c he rE di t i on, Gr a de5 Dividing Unit Fractions and Whole Numbers Plug In Multiplying Fractions FOUNDATIONAL UNDERSTANDING Plug In Multiplying Fractions Student Edition . pp. 134–135 power up Fractions as Division ON-LEVEL TARGET ready to go Dividing Unit Fractions and Whole Numbers MATERIALS • Math Tool: Fraction Strips, p. A15 (Student Edition p. 237) • Paper clips (suggested) english language learners MP6 ELL students may not understand why the terms each and in all indicate multiplication. Distribute . 2 paper clips to each of . 4 students. Explain that they each received 2 paper clips and there are 8 paper clips in all. Then, have students write 4 3 2 5 8. Repeat, as needed, to reinforce understanding. 106 Le ss o n 1 4 CC13_Mth_G5_TM_PDF.indd 106 OBJECTIVES CONCEPTS AND SKILLS VOCABULARY • Use a model and write an equation to multiply a whole number by a fraction. Interpret the product of a fraction times a whole number using visual models or by following a sequence of operations in which the whole number is renamed as a fraction and the numerators and denominators are multiplied. CCSS: 5.NF.4.a • Show a fraction as division to solve problems. Interpret a fraction as division of • divisor the numerator by the denominator. • mixed number Solve word problems involving • remainder division of whole numbers leading to answers in the form of fractions or mixed numbers. CCSS: 5.NF.3 • Divide whole numbers by unit fractions and unit fractions by whole numbers using models and writing equations. Solve mathematical and real-world problems involving division of unit fractions by whole numbers and division of whole numbers by unit fractions. CCSS: 5.NF.7.a, 5.NF.7.b, 5.NF.7.c • reciprocal • unit fraction Build Background Talk to students about reasons to multiply whole numbers and fractions 1 in real life. For example, Paul has 4 acres of farmland. He plants __ 3 of each acre with corn. How many acres of corn will he plant? Explain that multiplying fractions helps answer that question. MP4 Have students discuss additional examples of real situations that involve multiplying whole numbers and fractions. Tell students they will use models and equations to find the product of a fraction and a whole number. Introduce and Model Introduce Concepts Guide students through the information about multiplying fractions. MP5 Emphasize that the number of rectangles is the number of wholes and the number of parts in each whole is the denominator of the fraction. Support Discussion MP3 Have partners discuss briefly before group discussion. As needed, have students use the previous problems for reference to help them determine how each number in the problem should be represented. © 2014 Triumph Learning, LLC 17/05/13 6:00 PM Tatyanahas5cansofpaint .Each cancontains1gallonofpaint . 1 Tosolvetheproblemwithout amodel,writethewhole number,5,asafraction . Multiplythenumeratorsand thedenominators . Youcanuseamodelto representtheproblem . Sheuses__ 4ofeachcantomixa newcolor .Howmanygallonsof paintdoesshemix? 1 __ 4355p 2 __61375 A Youcanuseamodeltomultiplyawholenumbertimesafraction . 1 Multiply:43__ 3 3 Writetheproduct . 1 3 1 1 43__ 35 134 1 3 1 1 3 4 3 1 1 3 5 4 3 Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC WhatcanyoutellAvaabouthermodel? Possible response: It is not correct. She should have drawn 6 rectangles separated into 4 sections, with one section of each rectangle shaded. Addtheshadedparts . Writetheproduct . 1 73__415 1 2 3 1 1 3__ 10 5 1 3__ 10 15 3 1 1 3 10 5 15 10 15 10 4 7 6 Multiply. 3 63__51 6 1 1 3__ 55 6 3 1 1 3 5 5 6 5 4 __313 8 1 __ 33 8 1 5 1 3 3 8 3 1 5 8 3 135 Model Application A Guide students through modeling the number of wholes and the number of parts in each whole. DO B Monitor students as they find the product. Remind students that any whole number can be written as a fraction with a denominator of 1. Practice and Assess Ask students to complete practice items 1–4 on page 135 independently or in pairs. Monitor ongoing work. Observe whether students are writing the whole numbers as fractions before multiplying. Use the chart below, as needed, to address any difficulties. Observation Action Students do not multiply the fractions and whole numbers correctly. Have students use Math Tool: Fraction Strips to model the multiplication rather than draw models. Students should use the whole-number factor to determine the number of fraction strips and the fractional factor to determine the size of each strip. Have students compare the model to 1 whole to determine the product. CC13_Mth_G5_TM_PDF.indd 107 15 7 Lesson 1 4 © 2014 Triumph Learning, LLC 15 1 Prompt: How many rectangles are there? How many parts are in each rectangle? Sentence Starter: Ava’s model is/is not correct because… DO 1 153__ 10 5 Use the model to multiply. I get it! I can rename a whole number as a fraction by writing the whole number as a numerator over a denominator of 1! Avadrewthismodeltoshow__ 436 . 1 Show4groupsof__ 3 . Multiplythenumeratorsandthe denominators . I get it! I can write a whole number as a fraction with a denominator of 1. PRACTICE 5 Tatyanamixes__ 4 gallons of paint . Each shaded section 1 represents __ 4 of a gallon. There are 5 shaded sections. 1 2 1 5 The word “of” tells me to multiply. DO Renamethewholenumberasa fraction . 153__ 10 5 5__ 4 5 1 1 1 1 1 __ __ __ __ __ __ 41414141454 CU S S 1 Multiply:153__ 10 1 5 1 1 __ 43__ 1 4355__ 135 5____ 431 Writeanequationtorepresent theproblem . DIS DO Multiplying Fractions Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC LESSON Plug In B Youcanmultiplyawholenumbertimesafractionwithoutusingamodel . Lesson 14 14 14 Dividing Unit Fractions and Whole Numbers Dividing Unit Fractions and Whole Numbers spotlight on mathematical PRACTICES MP3 Critiquing Others’ Reasoning Help students think about Ava’s model critically by asking probing questions: What does the number of rectangles show? What does the number of parts in each rectangle show? What does the number of shaded parts show? D ividing U nit F ractions and Whole N umbers 107 17/05/13 6:00 PM power up Fractions as Division OBJECTIVES Plug In FOUNDATIONAL UNDERSTANDING Multiplying Fractions power up Fractions as Division Student Edition . pp. 136–137 ON-LEVEL TARGET ready to go Dividing Unit Fractions and Whole Numbers CONCEPTS AND SKILLS VOCABULARY • Use a model and write an equation to multiply a whole number by a fraction. Interpret the product of a fraction times a whole number using visual models or by following a sequence of operations in which the whole number is renamed as a fraction and the numerators and denominators are multiplied. CCSS: 5.NF.4.a • Show a fraction as division to solve problems. Interpret a fraction as division of • divisor the numerator by the denominator. • mixed number Solve word problems involving • remainder division of whole numbers leading to answers in the form of fractions or mixed numbers. CCSS: 5.NF.3 • Divide whole numbers by unit fractions and unit fractions by whole numbers using models and writing equations. Solve mathematical and real-world problems involving division of unit fractions by whole numbers and division of whole numbers by unit fractions. CCSS: 5.NF.7.a, 5.NF.7.b, 5.NF.7.c • reciprocal • unit fraction Build Background MATERIALS • Index cards (suggested) Talk to students about reasons to divide numbers in real life. For example, a 3-meter piece of string is cut into 4 equal pieces. How long is each piece? Explain that dividing 3 4 4 can answer this question. MP4 Have students discuss additional examples of real situations in which they divide numbers. Tell students they will divide whole numbers by writing them as fractions. Introduce and Model SPOTLIGHT ON MATHEMATICAL PRACTICES MP3 Critiquing Others’ Reasoning Help students think about Ella’s reasoning critically by asking probing questions: 1 What would a model for __ 3 look like? Does this describe each bar in Ella’s model? 108 Le ss o n 1 4 CC13_Mth_G5_TM_PDF.indd 108 Introduce Concepts and Vocabulary Guide students through the information about using fractions to divide. Emphasize that the fraction bar in a fraction is equivalent to a division sign. Use Words to Know to clarify students’ understanding of vocabulary. Have students explain to a partner the meaning of divisor, mixed number, and remainder. Support Discussion MP3 MP5 Have partners discuss briefly before group discussion. Students can use the models in the instruction for support. As needed, have students draw their own models to compare against Ella’s model. Prompt: How did Ella represent the divisor, 3? The dividend, 8? Sentence Starter: E lla’s model shows… © 2014 Triumph Learning, LLC 17/05/13 6:00 PM 14 Dividing Unit Fractions and Whole Numbers Fractions as Division Youcanwritethedivision problemasafraction .The fractionbarinafraction representsdivision .The valueofafractionisequalto itsnumeratordividedbyits denominator . Eachwholerepresents 1 granola bar .Divideeachwhole into3equalparts . remainder divisor 1 friend 1 1 4 __ 43__ 353 ofagranolabar 1 3 4 So,4435__ 3 . remainder theamountthatisleftover afterdivisioniscomplete divisor anumberbywhichanother numberisdivided 5 3 1 R2 5 3 1 R2 3 Elladrewamodeltoshowthat3485__ 8 .WhatcanyoutellEllaabouthermodel? Possible response: Ella should have shaded 3 parts of each whole instead of all 8 parts. 136 Writethequotientasafractionwith thedividendasthenumeratorand thedivisorasthedenominator . 3 Interpretthequotient . 4 5 5 Eachfriendwillget 1 Setupadivisionproblem . 2 Dividetowritethefraction asamixednumber . 3 Interpretthequotient . 5 Thedivisionproblemis 10 4 3 R 3 10 9 5 . 5 4 quartofwater . Threesistersequallysharethedrivingfora10-hour trip .Forhowmanyhoursdoeseachsisterdrive? 3 . I see! Since the numerator is greater than the denominator, I can divide to write the fraction as a mixed number! 1 1 10435 3 ____ 3 1 Lesson 1 4 Eachsisterwilldrivefor DIS CU S S 3 __ 3 hours . 25 Keishawantstowritethefraction___ 8 asdivision .Whichnumbershouldshewriteasthe divisor?Whichnumbershouldshewriteasthedividend? Keisha should write 8 as the divisor and 25 as the dividend. PRACTICE Solve. 1 Sixfriendsequallyshareabagofpopcorn .Thebagcontains9cupsofpopcorn .Howmany cupsofpopcornshouldeachfriendget? 3 1 __ 6 2 Charlottecutsa3-foot-longpieceofribboninto4equalpiecestotrimasquarepillow . Howlongiseachpieceofribbon? 3 __ 4 Model Application DO 4 4 4 1 1 CU S S 2 A fraction greater than 1 can be written as a mixed number. 1__ 6isamixednumber . DIS 4 Thedivisionproblemis Setupadivisionproblem . DO 1 gets1__ 3granolabars . The dividend is greater than the divisor, so the quotient is a fraction that is greater than 1! mixed number anumberthathasawholenumberpartandafraction part Fivefriendsequallyshare4quartsofwater .Howmanyquartsofwaterdoeseachfriendget? 1 B Youcanshowdivisionwithquotientsgreaterthan1asafraction . 1 So,44351__ 3,andeachfriend Eachfriendwillgetfour__ 3parts . Know 1 R1 3 4 3 1 Towritethequotientasa mixed number,writethe wholenumber,1,andwritethe remainderasthenumeratorof afractionwiththedivisorasthe denominator . 4 Words to DO 4 find__ 3 . 4435__ 3 I see! A fraction is another way to write a division problem! A Youcanshowdivisionwithquotientslessthan1asafraction . Youcanuselongdivisionto Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Thedivisionproblemis:443 . Youcanuseamodeltoshow 443 . Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC If3friendsshare4granolabars equally,whatpartofagranola bardoeseachfriendget? Lesson 14 POWER uP A Guide students through finding the quotient. Monitor that students write the divisor as the denominator. DO B Explain that since the fraction bar means division, the numerator can be divided by the denominator to find the quotient. Support Discussion MP6 MP7 Have partners discuss briefly before group discussion. As needed, point out to students the divisor in a division problem. Prompt: Which number is above the fraction bar? Which number is below the fraction bar? Sentence Starter: To write the fraction as a division problem, Keisha should write… 137 english language learners MP6 ELL students may require additional support for understanding the term divisor. Explain that many words in English that end in -or name the doer of an action, so the divisor does the dividing. Reinforce with examples such as an advisor advises and an inventor invents. Brainstorm additional examples. Practice and Assess Ask students to complete practice items 1 and 2 on page 137 independently or in pairs. Monitor ongoing work. Observe whether students correctly write and solve the division problems. Use the chart below, as needed, to address any difficulties. Observation Action Students write the divisor as the numerator of the fraction. Write “ _______ 5 __________ ” on the board. divisor denominator Have students refer to the equation on the board as they solve the problems. © 2014 Triumph Learning, LLC CC13_Mth_G5_TM_PDF.indd 109 dividend numerator focus on fluency MP5 Use index cards numbered from 1 to 20 to have students practice division. Place the cards numbered 1–5 in one stack to use as divisors. Place the remaining cards in another stack to use as dividends. Have students choose a card at random from each stack and find the quotient. D ividing Unit F ractions and Whole Numbers 109 17/05/13 6:00 PM Unit Fractions and Whole ready to go Dividing Numbers Plug In FOUNDATIONAL UNDERSTANDING Multiplying Fractions power up Fractions as Division OBJECTIVES ON-LEVEL TARGET MATERIALS • Lesson 14 Quiz, Assessment Manual . pp. 30–31 • Lesson 14 Quiz Answer Key, Assessment Manual VOCABULARY • Use a model and write an equation to multiply a whole number by a fraction. Interpret the product of a fraction times a whole number using visual models or by following a sequence of operations in which the whole number is renamed as a fraction and the numerators and denominators are multiplied. CCSS: 5.NF.4.a • Show a fraction as division to solve problems. Interpret a fraction as division of • divisor the numerator by the denominator. • mixed number Solve word problems involving • remainder division of whole numbers leading to answers in the form of fractions or mixed numbers. CCSS: 5.NF.3 ready to go • Divide whole numbers Dividing Unit Fractions and Whole Numbers Student Edition pp. 138–143 CONCEPTS AND SKILLS by unit fractions and unit fractions by whole numbers using models and writing equations. Solve mathematical and real-world problems involving division of unit fractions by whole numbers and division of whole numbers by unit fractions. CCSS: 5.NF.7.a, 5.NF.7.b, 5.NF.7.c • reciprocal • unit fraction Build Background Talk to students about reasons to divide unit fractions in real life. For example, Marion is expecting 12 guests at a party. She makes 5 cups of 1 punch and pours __ 2 cup of punch into each glass. Will she have enough glasses of punch? Explain that dividing by fractions can be used to answer this question. MP4 Have students discuss additional examples of real situations that require dividing by fractions. Tell students they will divide whole numbers by unit fractions and unit fractions by whole numbers. Introduce and Model english language learners MP6 Enhance students’ understanding of the term reciprocal by connecting it with cognates in native languages. Spanish: recíproca French: réciproque Italian: reciproco 110 Le ss o n 1 4 CC13_Mth_G5_TM_PDF.indd 110 Introduce Concepts and Vocabulary Guide students through the information about dividing unit fractions. Emphasize that students should start by modeling the quantity that will be divided (the dividend). Use Words to Know to clarify students’ understanding of vocabulary. Have students explain the meanings of reciprocal and unit fraction, and give examples of each. © 2014 Triumph Learning, LLC 17/05/13 6:00 PM 14 Dividing Unit Fractions and Whole Numbers READY TO gO Youcanusemodelstohelpyoudividea unit fractionbyawholenumber . 1 1 1 __ Todivide__ 244,startwithamodelfor2 . Todivide24__ 3,startwithamodelfor2wholes . Divideeachwholeinto3equalparts,orthirds . Thereareatotalof6equalparts . 1 Divideinto4equalparts .Eachpartis__ 8 . 1 2 1 1 1 1 1 8 8 8 8 1 3 Todividewithoutamodel,multiplythedividend bythereciprocalofthedivisor . 1 1 4 1 1 131 1 __ 2445__ 24__ 15__ 23__ 45_____ 2345__ 8 1 3 POWER uP You can show a fraction as division of the numerator by the denominator. 2 __ 55245 3 1 33__ 55__ 5 138 Solveforn . gO! I get it! I can use what I know about multiplying and dividing fractions and whole numbers to solve problems. OVERSET 1 cup 1 cup 1 2 1 2 1 2 3 Renamethewholenumberasafraction:35__1 Writethereciprocalofthedivisor:__ 2 Rewriteasmultiplication:__13__ 15__ 156 1 3 2 6 2 __ 1 1 2 1 __ 34__ 25nisrelatedton3253 . __ __ __ 63__ 2513252 53 4 I remember! To write the reciprocal of a fraction, switch the numerator and the denominator. 1 6 1 2 6 2 cup Usemultiplicationtocheck . 1 1 2 1 So,n56 . 1 6 ✓ Themodelsshow3cups .Eachcupisdividedinto 1 2equalparts,orhalves .Thereare6equal__ 2parts . 1 A Youcanusemultiplicationtodivideawholenumberbyafraction . DO 1 1 451 . 4and__ 4arereciprocals:43__ must have divided by a fraction, because when a whole number is divided by a fraction, the quotient is greater than the dividend and the divisor. lEssOn lInk Plug In 2 1 cup Therearesix__ 2-cupservingsofricein3cupsofrice . reciprocal anumberthatgivesaproductof1when multipliedbyasecondnumber Morgandivides5byanumberandgetsananswerof20 .BethanysaysthatMorgan’s answerisincorrectbecausethequotientshouldalwaysbelessthanthedividend .What can yousaytoBethany? Possible response: I can tell Bethany that Morgan You can use a model to multiply a fraction by a whole number. __ Theequation3425nrepresentstheproblem . 3 6 3 233 1 2 13__ 15_____ 1315__ 156 24__ 35__ 3 cups 1 1 1 3 Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC unit fraction afractionwith1asthenumerator CU S S 1 3 When dividing a whole number by a fraction, the quotient is greater than the dividend and the divisor. 1 1 __ 1 1 __ 2,__ 3,4,and__ 5areunitfractions . DIS 1 3 Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Know 1 3 1 Multiplythedividendbythereciprocalof thedivisor . When dividing a fraction by a whole number, the quotient is less than the dividend and the divisor. Words to 1 Howmany__ 2-cupservingsaretherein3cupsofrice? Youcanalsouseamodeltodivideawholenumber byaunitfraction . Lesson 14 Dividing Unit Fractions and Whole Numbers Renamethewholenumberasa fraction . 2 Writethereciprocalofthedivisor . 3 Rewriteasmultiplication .Writethe quotient . 4 DIS 1 Divide:24__ 5 1 Multiplytocheck . CU S S 25 2 1 2 1 3 1 __ 5 5 1 5 1 2 3 5 1 3 1 1 55 Check: 10 3__ 1 5 10 1 5 10 1 1 3__ 55 5 10 10 5 5 2 1 ___ Wesdivided__ 8by3andgotaquotientof24 .Wescheckedhisanswerbymultiplyingthe quotientbythedivisor .HowwillWesknowifhedividedcorrectly? 1 Possible response: If Wes multiplies the quotient, ___ 24 , by the divisor, 3, 1 the product should be the dividend, __ 8 . 139 Lesson 1 4 Support Discussion MP3 Have partners discuss briefly before group discussion. If needed, review the terms quotient and dividend. Prompt: Can you think of a divisor that would result in a quotient that is greater than 5? Sentence Starter: Morgan must have divided by a number that… lesson link Connect to Foundational Understanding Skills learned in the Plug In and Power Up are referenced in the Lesson Link. Explain that fractions can be divided just like whole numbers and that fraction division uses the same skills as multiplying fractions. spotlight on mathematical LANGUAGE MP6 Support students in using mathematical language as they work: What is the reciprocal of the divisor? What is the denominator of the unit fraction? Write the reciprocal of the unit fraction. Teach/Instruction Guide students through the information about solving word problems. Explain that in this problem, the dividend is a whole number and the divisor is a fraction. DO A Monitor students as they write the whole number as a fraction and the reciprocal of the divisor before they multiply. Support Discussion MP2 Have partners discuss briefly before group discussion. As needed, have students identify the quotient, dividend, and divisor before discussion. Prompt: What numbers will Wes multiply? What should his answer be? Sentence Starter: If Wes multiplies the quotient by the divisor, his answer… © 2014 Triumph Learning, LLC CC13_Mth_G5_TM_PDF.indd 111 D ividing Unit F ractions and Whole Numbers 111 17/05/13 6:00 PM 14 Dividing Unit Fractions and Whole Numbers READY TO gO PRACTICE Write an equation to solve. Use multiplication to check. Variables may vary. Use models to solve. 1 __41435 1 6 Howmany__81-foot-longtilesmustIsobelplaceinarowifshewantstherowtobe3feetlong? HINT The divisor tells you how many equal parts to 1 divide __ 4 . 12 1 4 3 1 __ 8 4 5 t 24 tiles 1 1 1 1 1 1 1 1 1 1 1 1 12 12 12 12 12 12 12 12 12 12 12 12 7 If6peopleequallyshare__21gallonofmilk,howmuchmilkwilleachpersonreceive? 1 2 64__415 24 1 1 1 1 1 1 __ 2 4 1 __ 2 gallon(s) 6 5 m 8 Craigused__41cupofsugartomake12cookies . 1 15 4 44__715 28 5 24__915 18 140 REMEMBER Multiply the quotient by the divisor to check your work. Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Divide. Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Howmuchsugarwasineachcookie? 3 __51435 I know! I can write an equation to solve each problem. Solve. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 1 ___ 48 cup 12 9 Meganbought4ouncesofcheese .Thecheese 1 wascutinto__ 3-ounceslices .Howmanyslices ofcheesedidshebuy? DIS CU S S Check That It’s Reasonable 1 oliviadivided6by__ 2andgotaquotientof3 . Isolivia’squotientlessthanorgreaterthanthedividend,6? less than Whenyoudivideawholenumberbyaunitfraction,youarefindingthenumberofpiecesinthewhole number .Shouldthequotientbelessthanorgreaterthanthewholenumber? greater than 1 Possible response: Olivia multiplied Whaterrordidoliviamakewhenshedivided6by__ 2? 1 1 2 . 6 3 __ 2 instead of dividing 6 by __ 1 Whatis6dividedby__ 2? 12 141 Less o n 1 4 ADDITIONAL PRACTICE Provide students with additional practice to model and solve: 1 1 1 1 __ 4 5 5 4 __ 4 3 __ 4 8 6 4 __ 5 2 Support Independent Practice 1–5 Remind students to read the HINT and REMEMBER. If needed, ask: Which number is the divisor? What is the reciprocal of the divisor? 6–7 Ensure that students are writing the whole number as a fraction. 8–9 How do you know which number is the divisor and which number is the dividend? Support Discussion MP2 Have partners discuss briefly before group discussion. As needed, have students draw models to show the division. Prompt: What is the relationship between 6 and 3? Sentence Starter: The relationship between 6 and 3 is… Problem Solving Model the Four-Step Method MP4 MP6 Guide students through the four-step method using think-aloud strategies. 1 Think Aloud Kara has 3 feet of ribbon. Each piece is __ 6 foot long. I need to 1 find the number of times __ 6 goes into 3. Support Problem-Solving Practice Have students use the Checklist as they complete each step. Prompt: How can you find the number of laps Max ran? Prompt: Did Alisha practice for more than or less than 4 hours? Prompt: How many sandwiches will Jervaise make? 112 Le ss o n 1 4 CC13_Mth_G5_TM_PDF.indd 112 © 2014 Triumph Learning, LLC 17/05/13 6:00 PM 14 Dividing Unit Fractions and Whole Numbers READY TO gO READ PlAn Rewrite division as multiplication using the reciprocal of the divisor. PRACTICE Use the problem-solving steps to help you. ribboN cuttiNG 1 Maxranatotalof5milesaroundatrack .Eachlap 1 was__ 8 mile .Zacharyran36lapsaroundthetrack . Who ran morelaps? Karaneeds16piecesofribbonforaquilt .Shecuta3-foot-longred 1 ribboninto__ 6-foot-longpieces .Doesshehaveenoughpiecesofribbon? CHECKLIST READ Max PLAN • Whatistheproblemaskingyoutofind? SoLVE pieces WhetherKarahasenough Lesson 14 PROblEm sOlvIng ofribbon CHECK • Whatdoyouneedtoknowtosolvethisproblem? 3 Thelengthoftheredribbonis feet . 1 __ 6 Thelengthofeachpieceis foot . 2 Lastmonth,Lauriepracticedpianofor__41houreachdayfor • Howcanyousolvetheproblem? Dividethelengthofthe sOlvE ribbon pieces bythelengthofthe atotalof4hours .Alishapracticedpianoon15days . Whopracticedonmoredays? . 3 4 1 SoLVE CHECK 5r 6 READ PLAN Laurie Writeanequation .Letr5thenumberofpiecesofribbon . CHECKLIST 3 1 3 6 1 5 3 3 6 1 3 1 5 18 1 r5 18 Thereare 18 piecesofredribbon . ChECk Multiplythenumberofpiecesofribbonbythelengthofeachpiece . Theproductshouldequalthelengthoftheribbonbeforeitwascut . 18 3 1 6 5 18 1 3 1 6 5 18 3 1 1 3 6 5 18 6 5 3 feet DoesKarahaveenoughpiecesofribbon? yes 142 Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Solve . 3 Jervaiseneedstomake20sandwichesforaparty .Hehas 1 6poundsofturkeyandheisusing__ 3poundofturkeyfor eachsandwich .Willhemakeenoughsandwiches? No CHECKLIST READ PLAN SoLVE CHECK 143 Lesson 1 4 Explore Student Thinking MP4 Invite students to explain how they solved the problems. Have partners compare their work on a problem and describe their results. COMMON ERRORS Students may write the reciprocal of the wrong fraction. Emphasize that they should write the reciprocal of the divisor. In each problem, have students identify the divisor and then write its reciprocal. Assess Use the table below to observe whether students accurately divide unit fractions and whole numbers and to address any difficulties, as needed, before the quiz. When students are ready, assign the Lesson 14 Quiz. 1 Observation Errors in division are frequent; general confusion about dividing unit fractions and whole numbers. Action Have students draw pictures to model all computations. Have them write an equation below the models. 2 Observation Makes occasional errors when dividing; some understanding of dividing unit fractions and whole numbers. Observation Writes, models, and solves problems involving division of unit fractions and whole numbers accurately. Action Provide additional practice problems for dividing unit fractions and whole numbers. Encourage students to model the computations. Action Assign the Lesson 14 Quiz. 3 © 2014 Triumph Learning, LLC CC13_Mth_G5_TM_PDF.indd 113 D ividing Unit F ractions and Whole Numbers 113 17/05/13 6:00 PM 14 Dividing Unit Fractions and Whole Numbers Plug In Multiplying Fractions Tatyana has 5 cans of paint. Each can contains 1 gallon of paint. 1 To solve the problem without a model, write the whole number, 5, as a fraction. Multiply the numerators and the denominators. You can use a model to represent the problem. She uses __ 4 of each can to mix a new color. How many gallons of paint does she mix? 5 1 1 __ __ 4 3 5 5 __ 4 3 1 135 5 ____ 4 3 1 5 5 __ 4 5 Tatyana mixes __ 4 gallons Write an equation to represent the problem. 1 __ 4 3 5 5 p 5 1 1 1 1 1 __ __ __ __ __ 4 1 __ 4 1 4 1 4 1 4 5 4 The word “of” tells me to multiply. of paint. I get it! I can rename a whole number as a fraction by writing the whole number as a numerator over a denominator of 1! Each shaded section 41 of a gallon. represents __ There are 5 shaded sections. DIS CU S S 1 Ava drew this model to show __ 4 3 6. What can you tell Ava about her model? A You can use a model to multiply a whole number times a fraction. DO 1 Multiply: 4 3 __ 3 1 1 Show 4 groups of __ 3 . 2 Add the shaded parts. 3 Write the product. 1 3 1 1 4 3 __ 3 5 134 1 1 5 Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC LESSON S uppor tCoa c h, Ma t he ma t i c s , S t ude ntE di t i on, Gr a de5 L e ss o n 1 4 CC13_Mth_G5_SE_PDF.indd 134 17/05/13 1:31 PM 14 Dividing Unit Fractions and Whole Numbers B You can multiply a whole number times a fraction without using a model. DO 1 Multiply: 15 3 __ 10 1 Rename the whole number as a fraction. 2 Multiply the numerators and the denominators. 3 Write the product. 1 1 15 3 __ 10 5 1 1 3 __ 10 5 1 I get it! I can write a whole number as a fraction with a denominator of 1. 3 __ 10 3 5 3 1 15 3 __ 10 5 PRACTICE Use the model to multiply. 1 7 3 __41 5 Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC 2 __61 3 7 5 Multiply. 3 6 3 __51 1 3 __ 5 5 3 5 3 4 __31 3 8 1 __ 3 3 5 3 5 3 135 CC13_Mth_G5_SE_PDF.indd 135 17/05/13 1:31 PM Fractions as Division If 3 friends share 4 granola bars equally, what part of a granola bar does each friend get? The division problem is: 4 4 3. You can write the division problem as a fraction. The fraction bar in a fraction represents division. The value of a fraction is equal to its numerator divided by its denominator. You can use a model to show 4 4 3. You can use long division to 4 find __ 3 . Each whole represents 1 granola bar. Divide each whole into 3 equal parts. 1 R1 3 4 3 1 To write the quotient as a mixed number, write the whole number, 1, and write the remainder as the numerator of a fraction with the divisor as the denominator. 4 4 4 3 5 __ 3 remainder divisor 1 friend 1 Each friend will get four __ 3 parts. 1 I see! A fraction is another way to write a division problem! 4 __ 4 3 __ 3 5 3 of a granola bar Know mixed number a number that has a wholenumber part and a fraction part 1 1 __ 6 is a mixed number. DIS 136 CU S S 1 So, 4 4 3 5 1 __ 3 , and each friend 1 gets 1 __ 3 granola bars. 4 So, 4 4 3 5 __ 3 . The dividend is greater than the divisor, so the quotient is a fraction that is greater than 1! Words to 1 3 remainder the amount that is left over after division is complete 5 3 1 R2 3 A fraction greater than 1 can be written as a mixed number. divisor a number by which another number is divided 5 3 1 R2 Ella drew a model to show that 3 4 8 5 __ 8 . What can you tell Ella about her model? Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC POWER UP L e ss o n 1 4 CC13_Mth_G5_SE_PDF.indd 136 17/05/13 1:31 PM 14 Dividing Unit Fractions and Whole Numbers A You can show division with quotients less than 1 as a fraction. DO Five friends equally share 4 quarts of water. How many quarts of water does each friend get? The division problem is 1 Set up a division problem. 2 Write the quotient as a fraction with the dividend as the numerator and the divisor as the denominator. 3 4 Interpret the quotient. 4 4 Each friend will get quart of water. Three sisters equally share the driving for a 10-hour trip. For how many hours does each sister drive? 1 Set up a division problem. 2 Divide to write the fraction as a mixed number. 3 Interpret the quotient. The division problem is Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC 4 . I see! Since the numerator is greater than the denominator, I can divide to write the fraction as a mixed number! 3 R 3 10 9 10 4 3 5 ____ Each sister will drive for CU S S DIS . 5 B You can show division with quotients greater than 1 as a fraction. DO 5 hours. 25 Keisha wants to write the fraction ___ 8 as division. Which number should she write as the divisor? Which number should she write as the dividend? PRACTICE Solve. 1 Six friends equally share a bag of popcorn. The bag contains 9 cups of popcorn. How many cups of popcorn should each friend get? 2 Charlotte cuts a 3-foot-long piece of ribbon into 4 equal pieces to trim a square pillow. How long is each piece of ribbon? 137 CC13_Mth_G5_SE_PDF.indd 137 17/05/13 1:31 PM Dividing Unit Fractions and Whole Numbers READY TO GO You can use models to help you divide a unit fraction by a whole number. 1 You can also use a model to divide a whole number by a unit fraction. 1 1 __ To divide __ 2 4 4, start with a model for 2 . To divide 2 4 __ 3 , start with a model for 2 wholes. Divide each whole into 3 equal parts, or thirds. There are a total of 6 equal parts. 1 Divide into 4 equal parts. Each part is __ 8 . 1 2 1 1 1 1 1 8 8 8 8 1 3 To divide without a model, multiply the dividend by the reciprocal of the divisor. 1 1 4 __ 1 1 131 1 __ __ __ _____ __ 2 4 4 5 __ 2 4 1 5 2 3 4 5 2 3 4 5 8 1 1 __ 1 1 __ __ 2 , __ 3 , 4 , and 5 are unit fractions. 1 3 1 2 3 6 233 __ __ _____ 5 __ 5 6 2 4 __ 1 3 5 1 3 1 5 1 3 1 reciprocal a number that gives a product of 1 when multiplied by a second number 1 1 __ 4 and __ 4 are reciprocals: 4 3 4 5 1. Morgan divides 5 by a number and gets an answer of 20. Bethany says that Morgan’s answer is incorrect because the quotient should always be less than the dividend. What can you say to Bethany? lesSon link Plug In You can use a model to multiply a fraction by a whole number. POWER UP You can show a fraction as division of the numerator by the denominator. 2 __ 5 5 2 4 5 1 3 __ 3 3 __ 5 5 5 138 1 3 When dividing a whole number by a fraction, the quotient is greater than the dividend and the divisor. unit fraction a fraction with 1 as the numerator CU S S DIS 1 3 GO! I get it! I can use what I know about multiplying and dividing fractions and whole numbers to solve problems. OVERSET Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Know 1 3 Multiply the dividend by the reciprocal of the divisor. When dividing a fraction by a whole number, the quotient is less than the dividend and the divisor. Words to 1 3 1 L e ss o n 1 4 CC13_Mth_G5_SE_PDF.indd 138 17/05/13 1:31 PM 14 Dividing Unit Fractions and Whole Numbers 1 How many __ 2 - cup servings are there in 3 cups of rice? 3 cups 1 1 __ The equation 3 4 2 5 n represents the problem. 2 Solve for n. 1 cup 1 cup 1 cup 1 2 1 2 1 2 3 Rename the whole number as a fraction: 3 5 __1 Write the reciprocal of the divisor: __ 2 Rewrite as multiplication: __1 3 __1 5 __1 5 6 So, n 5 6. 1 3 3 2 1 2 1 I remember! To write the reciprocal of a fraction, switch the numerator and the denominator. 1 __ 3 4 __ 2 5 n is related to n 3 2 5 3. __ __ __ 6 3 __ 2 5 1 3 2 5 2 5 3 6 1 2 6 2 cup Use multiplication to check. 1 1 2 1 4 6 2 __1 1 6 ✓ The models show 3 cups. Each cup is divided into 1 2 equal parts, or halves. There are 6 equal __ 2 parts. 1 There are six __ 2 - cup servings of rice in 3 cups of rice. A You can use multiplication to divide a whole number by a fraction. DO Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC 1 1 Divide: 2 4 __ 5 Rename the whole number as a fraction. 2 Write the reciprocal of the divisor. 3 Rewrite as multiplication. Write the quotient. 4 25 2 2 3 Multiply to check. CU S S 1 5 2 3 5 5 3 Check: DIS 1 __ 5 1 3 __ 5 5 1 3 __ 5 5 5 1 ___ Wes divided __ 8 by 3 and got a quotient of 24 . Wes checked his answer by multiplying the quotient by the divisor. How will Wes know if he divided correctly? 139 CC13_Mth_G5_SE_PDF.indd 139 17/05/13 1:31 PM Ready to Go practice Use models to solve. HINT The divisor tells you how many equal parts to 1 divide __ 4 . 1 __41 4 3 5 1 4 2 6 4 __41 5 1 1 1 1 1 Divide. 3 1 __ 5 4 3 5 4 4 4 __71 5 5 2 4 __91 5 140 REMEMBER Multiply the quotient by the divisor to check your work. Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC 1 L e ss o n 1 4 CC13_Mth_G5_SE_PDF.indd 140 17/05/13 1:31 PM 14 Dividing Unit Fractions and Whole Numbers Write an equation to solve. Use multiplication to check. 6 How many __81 - foot-long tiles must Isobel place in a row if she wants the row to be 3 feet long? 4 5 tiles 7 If 6 people equally share __21 gallon of milk, how much milk will each person receive? 4 5 gallon(s) I know! I can write an equation to solve each problem. Solve. 8 Craig used __41 cup of sugar to make 12 cookies. Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC How much sugar was in each cookie? 9 Megan bought 4 ounces of cheese. The cheese 1 was cut into __ 3 - ounce slices. How many slices of cheese did she buy? CU S S DIS Check That It’s Reasonable 1 Olivia divided 6 by __ 2 and got a quotient of 3. Is Olivia’s quotient less than or greater than the dividend, 6? When you divide a whole number by a unit fraction, you are finding the number of pieces in the whole number. Should the quotient be less than or greater than the whole number? 1 What error did Olivia make when she divided 6 by __ 2 ? 1 What is 6 divided by __ 2 ? 141 CC13_Mth_G5_SE_PDF.indd 141 17/05/13 1:31 PM Ready to Go Problem solving RIBBON CUTTING READ Kara needs 16 pieces of ribbon for a quilt. She cut a 3-foot-long red 1 ribbon into __ 6 - foot-long pieces. Does she have enough pieces of ribbon? PLAN • What is the problem asking you to find? Whether Kara has enough of ribbon • What do you need to know to solve this problem? The length of the red ribbon is feet. The length of each piece is foot. • How can you solve the problem? Divide the length of the SOLVE by the length of the . Write an equation. Let r 5 the number of pieces of ribbon. 5r 4 3 3 5 5 3 r5 There are CHECK pieces of red ribbon. Multiply the number of pieces of ribbon by the length of each piece. The product should equal the length of the ribbon before it was cut. 3 3 5 3 5 5 3 Does Kara have enough pieces of ribbon? 142 5 feet Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Solve. L e ss o n 1 4 CC13_Mth_G5_SE_PDF.indd 142 17/05/13 1:32 PM 14 Dividing Unit Fractions and Whole Numbers practice Use the problem-solving steps to help you. Rewrite division as multiplication using the reciprocal of the divisor. 1 Max ran a total of 5 miles around a track. Each lap 1 was __ 8 mile. Zachary ran 36 laps around the track. Who ran more laps? CHECKLIST Read Plan Solve Check 2 Last month, Laurie practiced piano for __41 hour each day for a total of 4 hours. Alisha practiced piano on 15 days. Who practiced on more days? CHECKLIST Read Plan Solve Duplicating any part of this book is prohibited by law. © 2014 Triumph Learning, LLC Check 3 Jervaise needs to make 20 sandwiches for a party. He has 1 6 pounds of turkey and he is using __ 3 pound of turkey for each sandwich. Will he make enough sandwiches? CHECKLIST Read Plan Solve Check 143 CC13_Mth_G5_SE_PDF.indd 143 17/05/13 1:32 PM
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