EXT 3-6 Sampler

19 ExplicitHandsOn Instruction MultiplyingaWholeNumberbyaFraction Step5 69 ©Math TeachersPress, Inc.,Reproduction by anymeans is strictly prohibited. 3. Lisa lives of amile from school. How far does shewalk to school in 3 days? Addition: ____________________ Multiplication: ________________ 4. A jar of peanut butter weighs of a pound. Howmuchwill 2 jars weigh? Addition: ____________________ Multiplication: ________________ Multiply by drawing a picture of addition and bymultiplying. Draw a picture of the addition fact. Then show the solution by adding fractions and bymultiplying fractions. Will practices the piano for of an hour each day. What part of an hour will he practice in 3 days? + + = ____ + = ____ Multiplication of aWholeNumber and a Fraction I couldadd 3 times. I knowmultiplication isashortcut foraddition. I couldmultiply the numerator (the topnumber) by3. = = + + 3 = ____hr. 1. 2 Picture of Addition Multiplication 2. 2 Picture of Addition Multiplication 2 = _____ Part B 2–4 2–4 3–4 3–4 1–8 1–8 1–4 1–8 1–4 1–8 1–4 3–8 2–4 3–8 2–4 3 x 2 x + + + = = = = 3 + = + = –8 3–8 6–8 2 x =3–8 6–8 + Lesson 24, 4ETeacherGuide 69 Objective56: Tomultiply awholenumber times a fraction by relating it to theoperationof additionof fractions. Multiplying aWholeNumber by aFraction Review the relationshipbetween addition and multiplicationofwholenumbers, emphasizing that multiplication is a shortcut for addition. Writeon theboard: There are5pairs of shoes by thebackdoor. Howmany shoes are there? Canyou solve thisproblembydrawingapicture? Canyou solve thisproblemby firstusingaddition and thenusingmultiplication? 2+2+2+2+2=10 and 5groups of 2=5 2=10 Addingup2 five times is the sameasmultiplying5 times2.Multiplication is a shortcut foraddition. Writeon theboard: Jake lives¼of amile from his grandmother’shouse. How fardoes Jakewalkon a round trip? What is a round trip? (going there andback) Canyou drawapictureof theproblemusing fraction circles? Draw2 shaded fraction circles of¼each. 1/4 + 1/4 = 2/4 We can solve thisproblemusingadditionorbyusing multiplication. Writeon theboard: Addition: + = of amile Multiplication: 2groups of =2 = of amile We see thatmultiplication is a shortcut for additionof wholenumbers and also a shortcutwith fractions. + = Read the information at the topof thepage together. Draw3 fraction circleswith¼shaded, as shown at the top of thepage. What is thepattern for solving thisproblemusing multiplication? (multiply thewholenumber times the numerator of the fraction) Have students complete thepageon their own. FractionMultiplicationProblems Have studentsmakeup awordproblem for problem1orproblem2on the student page. Collect, redistribute, anddiscuss theproblems. Skill Builders 56-1, 56-2, 56-3, 56-4, 56-6 48-3 (discounts) Conceptual Understanding + + 4.NF.3b, 4.NF.4, 4.NF.4a, 4.NF.4b, 4.NF.4c, 4.MD.2 Concrete Representational Abstract