Fractions On A Number Line

Transcription

LESSON8.5Fractions on a Number LineFOCUSCOHERENCERIGORLESSON AT A GLANCEF C R Focus:Common Core State Standards3.NF.A.2a Represent a fraction 1/b on a number line diagram bydefining the interval from 0 to 1 as the whole and partitioning it intob equal parts. Recognize that each part has size 1/b and that the endpoint of the partbased at 0 locates the number 1/b on the number line.3.NF.A.2b Represent a fraction a/b on a number line diagram by marking off alengths 1/b from 0. Recognize the resulting interval has size a/b and that its endpointlocates the number a/b on the number line.Also 3.NF.A.2MATHEMATICAL PRACTICESMP1 Make sense of problems and persevere in solving them. MP4 Model with mathematics.MP7 Look for and make use of structure.F C R Coherence:Learning ObjectiveRepresent and locate fractions on anumber line.Language ObjectiveStudents use the sequence words first, next,then, and finally to explain how you canrepresent and locate fractions on a number line.MaterialsMathBoard, Fraction Strips (see eTeacherResources), color pencilsStandards Across the GradesBeforeGrade 3 After2.MD.B.6 3.NF.A.2a 4.NF.B.33.NF.A.2bF C R Rigor:Level 1: Understand Concepts.Share and Show (Checked Items)Level 2: Procedural Skills and Fluency.On Your OwnLevel 3: Applications.Think Smarter and Go DeeperF C R For more about how GO Math! fosters Coherencewithin the Content Standards and Mathematical Progressionsfor this chapter, see page 441J.About the MathProfessional DevelopmentTeaching for DepthIn this lesson, students will be introduced to using anumber line to represent fractions.A number line is a measurement model. Fractions on anumber line represent the distance from 0 to the locationmarked on the number line. So, if the distance from 0 to1 is partitioned into 4 equal increments, the third markrepresents 3 4 because it is 3 4 of the distance from 0 to 1.It may help if students visualize the distance between0 and 1 as the whole and see the length between the tickmarks as fractional parts.Professional Development Videos467AChapter 8'' (( ()* The point represents the fraction 3 4 .

1 ENGAGEDaily RoutinesCommon CoreProblem of the Day 8.5Dan ordered a pizza. It was divided into8 equal slices. His brother ate 1 slice. Howmuch of the pizza did his brother eat?One eighth;18–––––––VocabularyEssential QuestionHow can you represent and locate fractions on anumber line?Making ConnectionsInvite students to talk about farms. Pose the following questions.Have you ever been to a farm where they grow a crop? What typesof food did they grow on the farm? Where do farmers sell theircrops?Learning Activity Interactive Student Edition Multimedia eGlossaryFluency Builderwith the Interactive Student EditionConnect the story to the problem.Common Core FluencyStandard 3.OA.C.7Division Facts Write the following divisionproblems on the board. Have studentspractice their division facts by solving eachproblem. Then have students check eachanswer by writing a related multiplicationfact.27 3 9; 3 9 2735 7 5; 7 5 3540 4 10; 4 10 4018 3 6; 3 6 1816 2 8; 2 8 1624 6 4; 4 6 2456 8 7; 8 7 5618 9 2; 9 2 18 What information are you given in this story? The potatoes are 1 4of the way to the vegetable stand. The onions are 3 4 of the way to thevegetable stand. When might you use a fraction to describe a distance? on a familytripLiteracy and MathematicsYou may choose one or both of the following activities. Ask students to describe how displaying the fractions on a numberline helps them determine the distances between the stops. Have students use rulers to draw number lines that represent daytrips they would like to take. Have them mark and label six placesof interest they’d like to visit or see at equal distances apart ontheir number lines. Invite students to share their number lines withthe class. Then have the students write a short story about whatthey would do on one of those day trips.How can you representand locate fractions ona number line?Lesson 8.5467B

LESSON8.53.NF.A.2a Represent a fraction 1/b on a number line diagram by defining the interval from 0 to 1 as the whole and partitioningit into b equal parts. Recognize that each part has size 1/b and that the endpoint of the part based at 0 locates the number1/b on the number line. 3.NF.A.2b Represent a fraction a /b on a number line diagram by marking off a lengths 1/b from 0.Recognize the resulting interval has size a/b and that its endpoint locates the number a/b on the number line.2 EXPLOREUnlock the ProblemLesson 8.5NameHandsOnFractions on a Number LineMP1 Make sense of problems andpersevere in solving them. Make sure thatstudents understand that the number linerepresents the complete trip in the problem. What does way mean? the total distance to Billy’sBilly’s family is traveling from his house to hisgrandma’s house. They stop at gas stations whenthey are 1 4 and 3 4 of the way there. How can yourepresent those distances on a number line? What does of the mean? part of the total1 of the way. What part One gas station is4of this fraction tells the number of equalparts? the denominator, 4 What does the numerator tell you? TheActivityBilly’s House0ActivityStudents rephrase modeled steps to showunderstanding of how fractions can equal onewhole. Have students fold a strip of paper intofourths. Have them color one fourth after the1.teacher models and explains why it is412344444STEP 2 At the end of each strip, draw a mark on the line. Houghton Mifflin Harcourt Publishing CompanySTEP 3 Count the fourths from zero to 1 to label the distances from zero.STEP 4 Think: 1 4 is 1 out of 4 equal lengths.Draw a point at 1 4 to represent the distance from 0 to 1 4 .Label the point G1.STEP 5 Think: 3 4 is 3 out of 4 equal lengths.Draw a point at 3 4 to represent the distance from 0 to 3 4 .Label the point G2.Chapter 8Reteach 8.52Lesson 8.5ReteachNameLesson 8.5EnrichNameFractions on a Number LineFraction FindWrite a fraction that names the shaded part ofeach whole. Then locate the fraction on thenumber line below. Write the letter of the modelthat represents the fraction.Use the fraction strips to help name the points on the number line.1.Draw a point to show3Step 1 The denominator is 3, so use fraction strips for thirds. Placethe fraction strips above the number line. Use the fractionstrips to divide the number line into three equal lengths.A.B.Step 2 Label each mark on the number line.1 of the totalThink: The distance between each mark islengths. 3distance, so count the number of 131Step 3 Draw a point on the number line to show .301.381131313031323331 of 3equal lengths2 of 3equal lengths3 of 3equal lengths141414234444Write the fraction that names the point.01606point A16A16Chapter Resources Houghton Mifflin Harcourt Publishing Company1626163.8-13point B51656468E.F.4416B3611141D.82.Complete the number line. Draw a point to show4068C.0 of 3equal lengths0467DifferentiatedInstructionEnrich 8.5312.467 Chapter 814Place four 1 4 -fraction strips end-to-end above the line to help. Continue to color each fourth until all parts4 equals one whole.are colored. Explain4 Ask students to rephrase in their own wordsto a partner why 4 4 equals one whole.14STEP 1 Divide the line into four equal lengths, or fourths.4 , or at2.between 0 and44RephraseGrandma’s House1G21404denominator of the fractions, which means there will be4 equal lengths in the whole.ELLG114MP4 Model with mathematics.Direct students’ attention to the number line. Why is the number line being divided into4 equal lengths? Possible answer: because 4 is theStrategy:Locate fractions on a number line.Materials fraction stripsnumber of equal lengths that have been traveled so far.Have students describe how they would makea number line for this situation if one werenot provided for them.MP2 Reason abstractly andquantitatively.1 Billy’s family stops for lunch when they are2of the way to his grandma’s house. Howwould you show this on the number line?How many fourths is this? Place a point halfwayA point on a number lineshows the endpoint of alength, or distance, fromzero. A number or fractioncan name the distance.You can use a number line to show fractions. Thelength from one whole number to the next wholenumber represents one whole. The line can bedivided into any number of equal parts, or lengths.distance3 equal lengths, or three fourths.HandsOnUnlockUnlock thethe ProblemProblemgrandma’s house How do you know where to draw a point3? The numerator is 3, so I counted from zerofor4Number and Operations—Fractions—3.NF.A.2a, 3.NF.A.2bAlso 3.NF.A.2MATHEMATICAL PRACTICESMP1, MP4, MP7Essential Question How can you represent and locate fractions on anumber line?MATHEMATICAL PRACTICES2888106608Reteach1CChapter Resources Houghton Mifflin Harcourt Publishing CompanyEA488-14DB78FEnrich

DO NOT EDIT--Changes must be made through “File info”CorrectionKey BDO NOT EDIT--Changes must be made through “File info”CorrectionKey BExampleHandsOnExampleGuide students to complete the numberline. Make sure that they understand thatthe denominators of the fractions match thenumber of equal lengths between two wholenumbers on the number line. What fraction names the point?  56 Whatdoes the numerator show? the number of equalComplete the number line to name the point.Materials color pencilsWrite the fraction that names the point on the number line.Think: This number line is divided into six equal lengths, or sixths.106.The length of one equal part is1616061616116161234566666lengths that are shaded663 EXPLAINShade the fraction strips to show the location of the point.5 out of6 equal lengths shaded.There areThe shaded length shows 5 6 .Share and Show5names the point.So,6BOARD131313012333331180818181828382. point A18A1848185818B18C88683. point BUse Math Talk to focus onstudents’ understanding of howthe number line connects to fractions.Possible explanation: 1 3 ofthe whole distance, or thelength, from zero to 1Write the fraction that names the point.0BOARDMathTalkMATHEMATICAL PRACTICES 4Use Models What doesthe length betweeneach mark on thisnumber line represent?784. point C Houghton Mifflin Harcourt Publishing Company0Mathalk1 T Houghton Mifflin Harcourt Publishing Company1. Complete the number line. Draw a point to show 23 .MATHThe first problem connects to the learningmodel. Have students use the MathBoard toexplain their thinking.MATHShareShare andand ShowShowHandsOnUse the checked exercises for Quick Check.Students should show their answers for theQuick Check on the MathBoard.3Rt ICheckaQuickstudent missesthe checkedRt IQuick Check2132If1exercisesIf468Then3 MNLESE342149 C08L05.indd 46815/10/14 11:18 PMVisual / arnersPartnersMaterials Fraction Strips (see eTeacher Resources) Write the following problem on the board.Mr. Smith is driving to work. He stops for breakfast1 of the way to work.How can you show thiswhen he is 2distance on the number line? Have one student choose the fraction strips that willrepresent the problem. Then the partner draws a numberline and uses the fraction strips to show the distance onthe number line.Differentiate Instruction with Reteach 8.5 Personal Math Trainer3.NF.A.2a, 3.NF.A.2b RtI Tier 1 Activity (online)COMMON ERRORSError Students do not label a point on theCOMMONnumberline correctly. ERRORSExample For Exercise 1, a studentmay label the point at   1 instead of  2 .3Springboard to Learning Have students3use a shading method to correct the error.0 to  13 , and then  13 to  23 Students shade from 32to understand that  3 represents the distancefrom 0 to that point.Lesson 8.5468

NameOn Your OwnOnOn YourYour OwnOwnIf students complete the checked exercisescorrectly, they may continue with the On YourOwn section. How many fraction strips do you need forthe number line in Exercise 5? How do youknow? Possible answer: I see that the number lineUse fraction strips to help you complete the numberline. Then locate and draw a point for the fraction.25.61016shows sixths, so I need 6 sixth strips. When looking at the number lines, how doyou know what numbers to write for eachfraction? Possible answer: I look to see how many06equal parts are shown between 0 and 1 and I write thatnumber for the denominator. Then I look to see howmany parts away from the 0 it is and write that numberas the numerator.26.31234566666066113MP4 Model with mathematics. To extendtheir thinking, have students draw a numberline on notebook paper to represent the5. Students could present theirfraction8number lines to the class.03123333Write the fraction that names the point.01C041E48. point D10. There is a walking trail at the park.443247. point C Houghton Mifflin Harcourt Publishing CompanyD49. point EDEEPERFour laps around the trail is a distanceof 1 mile. How many laps does it taketo walk 3 4 mile?A recipe for pasta makesenough for eight servings. How manyservings can be made using 4 8 of eachingredient in the recipe?3 laps4 servings11.Chapter 8 Lesson 5469 Chapter 8469

MATHEMATICAL PRACTICESANALYZE t -00, '03 4536 563& t 13& *4*0/4 ELABORATEUnlockUnlock thethe ProblemProblem12.Javia ran 8 laps around a track to runa total of 1 mile on Monday. How many laps will sheneed to run on Tuesday to run 3 8 of a mile?SMARTERUnlock the Problemb. How will you use whatyou know about numberlines to help you solvethe problem?a. What do you need tofind?the number of lapsJavia will need to runPossible answer: I willon Tuesdayuse the number line toMATHEMATICAL PRACTICESSMARTERHave students read Exercise 12. Ask them todescribe how they will solve the problem.MP4 Model with mathematics. How do you know how many equallengths to show on your number line?countthe number of lapsinthree eighths of a mile.c.MATHEMATICALPRACTICE4Use Models Make a model to solve the problem. Check students’ models.0The total distance is 8 laps, so the number line willhave 8 equal lengths.118181808181818181838Math on the SpotVideo Tutor88d. Complete the sentences.Use this video to help students model andsolve this type of Think Smarter problem.8 laps in 1 mile.There are18of a mile.Each lap representsMath on the Spot videos are in the InteractiveStudent Edition and at www.thinkcentral.com.Three laps represent the distance of three eighths of a mile.3 laps to run 3 of a mile.So, Javia will need to run813.Locate and draw point F on the numberline to represent the fraction 2 4.SMARTER01F Houghton Mifflin Harcourt Publishing CompanySMARTERPersonal Math Trainer470DIFFERENTIATED INSTRUCTIONDINDEPENDENT ACTIVITIESPersonal Math TrainerBe sure to assign this problem to studentsin the Personal Math Trainer. It features ananimation to help them model and answerthe problem. This item assesses a student’sability to locate a fraction on a numberline. Students should understand that each1 . An incorrectly plottedequal part shows43may show that students did notpoint at44 maystart counting from zero. A point at4indicate confusion between numerator anddenominator meanings.5 EVALUATE FormativeAssessmentEssential QuestionDifferentiated Centers KitUsing the Language ObjectiveActivitiesFish for FractionsStudentscompleteorangeActivityCard 11 byplaying a Go Fish game inwhich they match fractionsymbols, words, andpictures.LiteraturePizza Parts!Students readabout howto find equalparts to writefractions.Reflect Have students use the sequencewords first, next, then, and finally to answerthe Essential Question.How can you represent and locate fractionson a number line? Possible answer: I divide thenumber line into equal lengths and draw a mark on theline at the end of each equal length. To locate a fraction,I use the numerator to count the number of equallengths.Math JournalWRITEMathExplain how showing fractions with modelsand a number line are alike and different.Lesson 8.5470

Practice and HomeworkLesson 8.5NameFractions on a Number LineUse fraction strips to help you complete the number line.Then locate and draw a point for the fraction.Practice and Homework011.3Use the Practice and Homework pages toprovide students with more practice of theconcepts and skills presented in this lesson.Students master their understanding as theycomplete practice items and then challengetheir critical thinking skills with ProblemSolving. Use the Write Math section todetermine student’s understanding of contentfor this lesson. Encourage students to use theirMath Journals to record their answers.COMMON CORE STANDARDS—3.NF.A.2a,3.NF.A.2b Develop understanding of fractionsas numbers.11303132333Write the fraction that names the point.008118A38282. point A48B68C88583. point B784. point CProblemProblem SolvingSolving5. Jade ran 6 times around her6. A missing fraction on a number lineneighborhood to complete a totalof 1 mile. How many times will sheneed to run to complete 5 6 of a mile?is located exactly halfway between3 and 5 . What is the missing fraction?66 Houghton Mifflin Harcourt Publishing Company5 times7.46Math Explain how showing fractions withWRITEmodels and a number line are alike and different.Check students' work.Chapter 8PROFESSIONALDEVELOPMENTMathematical Practices in Your ClassroomCCSS.Math.Practice.MP4 Model with mathematics.Students should recognize that while each fraction model comparesequal parts to the whole, one model may be more useful thananother in a given problem situation. Students should masterselecting the most useful model for the problem situation.The area model shows parts that have equal areas and is best usedfor partitioning whole objects. The linear model shows lengthsthat are compared instead of areas. While both fraction strips andnumber lines are linear models, the number line model is moresophisticated and is best used for problems involving distances fromzero. In this lesson, students use fraction strips to transition intousing a number line model for fractions that describe lengths anddistances.471 Chapter 8471Ask questions such as the following to help students connect distanceto fractions on a number line: How do you show the entire distance on the number line? From0 to 1 shows the entire distance; it shows one whole.1 of a complete trip, where would you write If a distance was4the fraction on the number line? I would count one equal part onthe number line and write the fraction at that point. What type of real-world situations can be modeled using afraction circle? using a number line? Explain. Possible answer:I can use a fraction circle to model dividing a pie into equal slices.I can use a number line to model the distance the bus travels frommy house to school, and the stops it makes along the way.

Lesson Check (3.NF.A.2a, 3.NF.A.2b)1. What fraction names point G on thenumber line?number line?004G2. What fraction names point R on the2434104403Continue concepts and skills practice withLesson Check. Use Spiral Review to engagestudents in previously taught concepts andto promote content retention. Common Corestandards are correlated to each section.1R13143323Spiral Review (3.OA.B.5, 3.OA.C.7, 3.NF.A.1)3. Each table in the cafeteria can seat10 students. How many tables areneeded to seat 40 students?4. Use the Commutative Property ofMultiplication to write a relatednumber sentence.4 9 364 tables5. Pedro shaded part of a circle. What9 4 366. Find the quotient.8 1 Houghton Mifflin Harcourt Publishing Companyfraction names the shaded part?878FOR MORE PRACTICEGO TO THE472Personal Math TrainerLesson 8.5472

About the Math Professional Development LESSON AT A GLANCE Professional Development Videos Teaching for Depth In this lesson, students will be introduced to using a number line to represent fractions. A number line is a measurement model. Fractions on a number line represent the d