s e s s i o n 1 . 1 a subtraction facts · 2018. 9. 6. · • student activity book, p. 1a or ......

s e s s i o n 1 . 1 A

Activity

Addition Combinations and Related Subtraction Facts 20 Min clAss PAirs

•Connectingcubes;Makeacubetowerof8:7 yellowand1red.

•Connectingcubes(10perstudent)

Activity

Which Subtraction Facts Do I Know? 30 Min individuAls PAirs

•c2–c6, subtraction cards sets: 1–3Makecopiesandcutapart.(1setperstudent)

•Envelopes(2perstudent)

Activity

Writing Addition Clues10 Min clAss individuAls

•Student Activity Book,p.1Aorc7, Practicing with subtraction cardsMakecopies.(asneeded)

•Connectingcubes(asneeded)

session Follow-uP

Daily Practice and Homework •Student Activity Book,p.1Aorc7, Practicing with subtraction cards Makecopies.(asneeded)

•Student Activity Book,p.1Borc8, subtraction Facts Makecopies.(asneeded)

today’s Plan Materials

Subtraction FactsMath Focus Points

Developing fluency with the subtraction facts related to the Plus 1, Plus 2, and Make 10 addition combinations

Classroom RoutinesQuick Images: Double Arrays Using the transparent double arrays from Rectangular Arrays (T24), display the 2 × 4 array. Follow the basic Quick Images activity. Students determine the total number of squares and share how they determined the amount. Record an equation using addition (e.g., 4 + 4 = 8) that represents the array. Repeat with 2 × 7 and 2 × 9.

session 1.1A subtraction Facts cc9

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Rectangular Arrays

Unit 2 Sessions 2.6, 3.1

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A C T I V I T Y

Addition Combinations and Related Subtraction Facts

ClAss pAIrs20 MIn

Begin this session by referring to the sets of addition combinations that students worked on and were assessed on in the previous unit.

You each have sets of cards for the Plus 1, Plus 2, and the Make 10 combinations. Today, we are going to look at some subtraction problems that are related to these addition combinations.

Write the following on the board, and have students record them on a piece of paper.

7∙ 1∙ _____8∙ 1∙ _____8∙ 7∙ _____

Here are three problems that are related to one another. Solve each of the problems, and then talk with a partner about how you think these problems are related.

Most students will quickly solve these problems, and many will recognize that they can use what they know about one problem (7 + 1 = 8) to solve the related subtraction problems (8 – 1 = 7 and 8 – 7 = 1).

Show students the tower of 8 cubes (7 yellow and 1 red) that you have prepared. Ask volunteers to explain how the problems in this set are related using the cubes to demonstrate their ideas. As students explain their thinking, model it for the class.

Studentsmightsay:“8isequaltoagroupof7plusagroupof1.Ifyoutakeawaythe7yellow,youareleftwith1red,andifyoutakeaway1red,youareleftwiththe7yellow.”

“Subtractionisliketheoppositeofaddition.Eitheryouputthegroupstogetheroryoutakethemapart.Ifyouknow7∙ 1is8,thenyouknow8takeaway1is7and8takeaway7is1.”

1 Activity 2 Activity 3 Activity 4 session Follow-Up

▲ T24

CC10 InVesTIgATIon 1 Features of 2-Dimensional and 3-Dimensional shapes

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1 Activity 2 Activity 3 Activity 4 Session Follow-Up

7 + 1 = 8

I wonder whether this will work for other addition combinations.

Write the following on the board, and have students record them on a piece of paper.

5 ∙ 2 ∙ _____ 7 ∙ 3 ∙ _____7 ∙ 2 ∙ _____ 10 ∙ 3 ∙ _____7 ∙ 5 ∙ _____ 10 ∙ 7 ∙ _____

Here are two other sets of problems. Solve each problem, and build a cube model of each set. Then talk with a partner about how the problems are related.

When students are finished, briefly discuss their thinking about how these sets of problems are related. 1

A C T I V I T Y

Which Subtraction Facts Do I Know?

IndIVIdUAlS pAIrS30 MIn

In the previous unit you were working on three sets of addition combinations, the Plus 1, Plus 2, and Make 10 combinations. Just as it is important to quickly know addition combinations with small numbers, it is also important to be able to quickly solve subtraction problems with small numbers. Today, you are going to get sets of subtraction fact cards that are related to the addition facts you already know.

Refer to the sets of problems that students just worked on as examples of each set. 2

Related to Related to Related to +1 combinations +2 combinations combinations of 10

8 – 1 = ___ 7 – 2 = ___ 10 – 3 = ___8 – 7 = ___ 7 – 5 = ___ 10 – 7 = ___

Teaching notes1 BuildingFluencywithSubtraction

Facts Students build on their growing understanding of the inverse relationship between addition and subtraction, as well as their fluency with addition combinations, to learn the related subtraction facts. Students will work on sets of subtraction facts in Units 2, 4, 5, and 9, following the assessment of a set of related addition facts (i.e., in Unit 1 students are assessed on the Plus 1, Plus 2, and Make 10 addition combinations. In Unit 2 they work on the related sets of subtraction facts). You can use this session as a model for introducing new sets of facts as indicated in subsequent units.

2 SubtractionFactsRelatedtoAdditionCombos Point out to students that one set has Subtraction Facts related to the +1 addition combinations, one set has Subtraction Facts related to the +2 combinations, and one set has Subtraction Facts related to the combinations of 10.

Session 1.1A Subtraction Facts CC11

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C6 © Pearson Education, Inc., or its affiliates. All Rights Reserved. 2


Unit 2 Session 1.1A

Subtraction Cards: Set 3 (page 5 of 5)

10 − 9

Clue:

10 − 8

Clue:

10 − 7

Clue:

10 − 6

Clue:

10 − 5

Clue:

10 − 4

Clue:

10 − 3

Clue:

10 − 2

Clue:

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Unit 2 Session 1.1A


5 − 3

Clue:

6 − 4

Clue:

7 − 5

Clue:

8 − 6

Clue:

9 − 7

Clue:

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Unit 2 Session 1.1A


4 − 2

Clue:

5 − 2

Clue:

6 − 2

Clue:

7 − 2

Clue:

8 − 2

Clue:

9 − 2

Clue:

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Unit 2 Session 1.1A


10 − 1

Clue:

3 − 2

Clue:

4 − 3

Clue:

5 − 4

Clue:

6 − 5

Clue:

7 − 6

Clue:

8 − 7

Clue:

9 − 8

Clue:

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Unit 2 Session 1.1A


2 − 1

Clue:

3 − 1

Clue:

4 − 1

Clue:

5 − 1

Clue:

6 − 1

Clue:

7 − 1

Clue:

8 − 1

Clue:

9 − 1

Clue:

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Distribute the three sets of Subtraction Cards (C2–C6) to each student. Explain to students that they should write their initials on the back of each card. Tell them that they should not write the answers to the problems on the cards, and for now, they should leave the Clue: blank.

Once students have initialed their cards, give each student two envelopes. Have students write their name on both envelopes and label one with “Subtraction Facts I Know” and the other with “Subtractions Facts I Am Still Working On.”

The Subtraction Cards are going to work just like your Addition Cards. Look through the cards and sort them into two groups. If you look at a card and you know the answer without having to stop and solve the problem, put that card in the “Subtraction Facts I Know” envelope. Put the cards that you aren’t sure about or have to stop and figure out the answer to in the “Subtraction Facts I Am Still Working On” envelope.

As you circulate, take subtraction cards from each student’s “Subtraction Facts I Know” envelope and see whether you agree that the student knows these facts. Re-file cards as needed.

Have pairs of students work together to practice with the cards. They should mix up the sets of cards so that related cards (i.e., Subtraction Cards related to +1 combinations) are not together.

OngOing ASSeSSment: Obser ving Student s at Work

Studentspracticethesubtractionfactsrelatedto+1and+2combinationsandcombinationsof10. 3

• Whichsubtractionfactscanstudentsrecallfluently?Whichdotheyneedtofigureout?

• Arestudentsabletoidentifytherelatedadditioncombinationandusethisinformationtohelpthemsolveanunknownsubtractionfact?

diFFerentiAtiOn: Suppor ting the range of Lear ner s

Somestudentsmayfindithelpfultosorttheircardsintosetsandpracticeeachsettogether.Forstudentswhohavealotofcardsinthe“StillWorkingOn”envelope,checktoseeiftheyarefluentwiththerelatedadditioncombinationcards.Thosestudentswhoarenotyetfluentwiththesecombinationsshouldpracticeworkingwiththeiradditioncombinationcardsfromthepreviousunit.

Reviewthephrases“factsIknow”and“factsIamworkingon”bysortingwithstudentsafewcardsthatshowexamplesofeach.

teaching note3 PracticingSubtraction

Facts Throughout this unit and in subsequent units, students should continue to practice the subtraction facts in their “working on” piles. This practice can be assigned as additional homework, a Math Workshop activity, or something students work on when they have a few minutes after completing another activity. C7 allows you to individualize this practice according to student needs.

▲ resource masters, C2–C6

CC12 inveStigAtiOn 1 Features of 2-dimensional and 3-dimensional Shapes

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DateNameShapes, Blocks, and Symmetry Homework

Session 1.1A Unit 2

Practicing with Subtraction CardsChoose 6 Subtraction Card problems from your “working on” pile, and write these on the blank cards below. Practice these at home with a friend or family member.

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

note Students practice subtraction facts and use related addition facts to help.

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DateNameShapes, Blocks, and Symmetry Daily Practice

1B Unit 2 Session 1.1A

Subtraction FactsSolve the subtraction problems.

10 − 3 = 8 − 2 = 7 − 5 =

9 − 1 = 10 − 7 = 10 − 4 =

8 − 6 = 5 − 1 = 8 − 7 =

Write subtraction facts that relate to these addition combinations.

8 + 1 = 9

− =

− =

7 + 2 = 9

− =

− =

9 + 1 = 10

− =

− =

note Students solve subtraction problems related to addition combinations.

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A c t i v i t y

Writing Addition Clues clASS10 Min individUAlS

After most students have sorted and practiced their sets of Subtraction Cards, call the group together to discuss how to use the Clue on each Subtraction Card.

Write following problems on the board.

9∙ 2 10∙ 4

Clue:____________ Clue:____________

Suppose you were stuck on these two subtraction facts. Talk with the person next to you about what addition problem you could use as a clue to solve the subtraction problem.

Ask volunteers to explain their thinking about which addition problem they would record. Use cubes to model their ideas.

Explain to students that they should work with a partner to write addition clues for any of the cards that are in the “Subtraction Facts I Am Still Working On” envelope. Each student should work on his or her own set of cards but can consult with a partner if they need a suggestion about the related addition clue. 4

Have students choose 6 problems from their “Working On” envelopes that they want to practice at home. They record those subtraction facts on Student Activity Book page 1A or C7.

S e S S i o n F o l l o w - U p

Daily Practice and Homework DailyPractice: For ongoing review, have students complete

Student Activity Book page 1B or C8.

Homework: Students work on the subtraction facts they recorded on Student Activity Book page 1A or C7 at home with a friend or family member.

teaching notes4 AssessingSubtractionFacts Most

students should be comfortable with most of these first sets of Subtraction Facts. Students will be assessed on these three sets of facts in Session 2.10A as a part of the End-of-Unit Assessment.

▲ Student Activity Book, Unit 2, p. 1A;Resource Masters, c7

▲ Student Activity Book, Unit 2, p. 1B;Resource Masters, c8

Session 1.1A Subtraction Facts cc13

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Unit 2 Session 1.1A


2 − 1

Clue:

3 − 1

Clue:

4 − 1

Clue:

5 − 1

Clue:

6 − 1

Clue:

7 − 1

Clue:

8 − 1

Clue:

9 − 1

Clue:

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Unit 2 Session 1.1A


10 − 1

Clue:

3 − 2

Clue:

4 − 3

Clue:

5 − 4

Clue:

6 − 5

Clue:

7 − 6

Clue:

8 − 7

Clue:

9 − 8

Clue:

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Unit 2 Session 1.1A


4 − 2

Clue:

5 − 2

Clue:

6 − 2

Clue:

7 − 2

Clue:

8 − 2

Clue:

9 − 2

Clue:

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Unit 2 Session 1.1A


5 − 3

Clue:

6 − 4

Clue:

7 − 5

Clue:

8 − 6

Clue:

9 − 7

Clue:

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Unit 2 Session 1.1A


10 − 9

Clue:

10 − 8

Clue:

10 − 7

Clue:

10 − 6

Clue:

10 − 5

Clue:

10 − 4

Clue:

10 − 3

Clue:

10 − 2

Clue:

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Shapes, Blocks, and Symmetry

DateName

Unit 2 Session 1.1A

note Students practice subtraction facts and use related addition facts to help.

Practicing with Subtraction CardsChoose 6 Subtraction Card problems from your “working on” pile, and write these on the blank cards below. Practice these at home with a friend or family member.

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

− =

Addition Clue:

Homework

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Shapes, Blocks, and Symmetry

DateNameDaily Practice

Unit 2 Session 1.1A

note Students solve subtraction problems related to addition combinations.

Subtraction FactsSolve the subtraction problems.

10 − 3 = 8 − 2 = 7 − 5 =

9 − 1 = 10 − 7 = 10 − 4 =

8 − 6 = 5 − 1 = 8 − 7 =

Write subtraction facts that relate to these addition combinations.

8 + 1 = 9

− =

− =

7 + 2 = 9

− =

− =

9 + 1 = 10

− =

− =

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s e s s i o n 1 . 1 a subtraction facts · 2018. 9. 6. · • student activity book, p. 1a or ......

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