EXT K-2 Sampler

47 Objective 26: To solve additionproblems in vertical andhorizontal format. PD Materials: Interlocking cubes, 10-sideddice, Addition-SubtractionMat (Master 3) Vocabulary: sum, equal sign ( =), number sentence Using aModel Each student shouldhave anAddition-Subtraction Mat (Master 3) touse as agraphicorganizer, and at least 10 interlocking cubes. Explain that themat will showhow thenumbers in addition are related. Review actingout the additionproblem2+3 from page8.Ask students toput anumber of cubes to match thenumber of studentswhowere standing at thedoor in theupper left corner of themat and thenumber of studentswhowere standingby the window in the right corner of themat. Weare showing twopartsof theproblem. Nowhave students bring the cubes together in the lowerpart of themat to show the sum.As the2 and 3 aremoved to the lowerpart of themat, emphasize that “apart plus apart equals thewhole.” Write theproblem inboth formats on theboard: 2 2+ 3= 5 + 3 5 Theanswer inaddition is called the sum . The= sign is anequal sign . Thenumbersonone sideof theequal signareequal to thenumberon theother side.Whenwewritenumbers, anoperation sign, andanequal sign together,wemakeanumber sentence. Repeatwith several examples. What is addition? (Additionmeans toput numbers together.) What is theanswer inanadditionproblem? (The answer in an additionproblem is the sum.) Direct attention to the topof thepage.Have studentsuse cubes of twodifferent colors to show 4+1on theAddition-SubtractionMat as a train (horizontal) and as a tower (vertical) and say “part plus part equalswhole.”Have studentsuse cubes on theAddition-SubtractionMat forproblems 1–6 and mentalmath forproblems 7–12. MakingTowers of Ten Each groupof 2 to 4players should have a 10-sideddie and interlocking cubes in a center pile. Round 1begins as Player 1 throws a die 6 times. After each throw, he starts a towerwith the number thrown (e.g., if the die lands on 2, 3, 5, 1, 7 and 6, he starts his 6 towerswith 2 cubes, 3 cubes, 5 cubes, 1 cube, 7 cubes, and 6 cubes). Eachof the other players repeats the activity. After the first round, players take turns throwing thedieone time each. They try to add thenumber thrown to their towers tomake each tower exactly 10 cubeshigh. For example, if Player 1now throws a 5, he couldput the5 cubes on the topof the1, 2, 3or 5 tower, but thebest choicewouldbe toput it on the topof the5 tower tomake a10. (Note: adding5 cubes to the6or 7 cube towerswouldmake the towers greater than10.) All the cubes fromeach throwmust beusedon the same tower. Players lose a turn if they roll anumber that cannot beplayed. The first player to roll thedice andget exactly 6 towers of 10 cubeswins. Skill Builders 26-1, 26-2, 28-9 9 ©Math TeachersPress, Inc.Reproduction by anymeans is strictly prohibited. Using aModel Build the numbers on themat. Put the numbers together. Write the answer. 1. 2 + 2 2. 3 + 2 3. 2 + 3 4. 5 + 0 = ______ 7. 2 + 1 = ______ 5. 2 + 4 = ______ 8. 0 + 3 = ______ 6. 1 + 3 = ______ 9. 1 + 4 = ______ 10. There are 5 books on the table and 1 book on the shelf. Howmany books are there in all? __________ 11. There are 4 students by thewindow and 2 students by the door. Howmany are there altogether? __________ Add. When we put two numbers together, we are adding. = 4 + 1 = 5 4 + 1 5 sum 4 + 1 = 5 sum The + signmeans to add. The answer is called the “sum.” We can write the problem twoways. 4 4 5 6 3 5 6 6 3 5 5 Lesson 4, 1ETeacherGuide 9 1.OA.1, 1.OA.6, 1.NBT.4 UsingaModel Grade1