2nd Grade - content.njctl.orgcontent.njctl.org/courses/math/2nd-grade/2-digit-addition-subtraction/2... · 2nd Grade Two Digit Addition and Subtraction 2015-12-03 Slide 3 / 291 click

Slide 1 / 291 Slide 2 / 291

2nd Grade

Two Digit Addition and Subtraction

2015-12-03

www.njctl.org

Slide 3 / 291

click on a topic to go to that section

Table of ContentsPresentation 1

Addition

Subtraction

Mixed Practice

Mentally adding and subtracting 10 and 100

Lab: Give and Take

Slide 4 / 291

Standards for Mathematical Practices

MP8 Look for and express regularity in repeated reasoning.

MP1 Make sense of problems and persevere in solving them.

MP2 Reason abstractly and quantitatively.

MP3 Construct viable arguments and critique the reasoning of others.

MP4 Model with mathematics.

MP5 Use appropriate tools strategically.

MP6 Attend to precision.

MP7 Look for and make use of structure.

Click on each standard to bring you to an example of how to meet

this standard within the unit.

Slide 5 / 291

Mentally Adding 10

Mentally Subtracting 10

Review adding and subtracting 10

Adding and subtracting 100

Review Adding and Subtracting 10 and 100

Mentally adding and Subtracting 10 and 100

click on a topic to go to that section

Click to return to Table of Contents

Lab: Carpet Square Math

Slide 6 / 291

Mentally Adding 10


http://www.njctl.org

http://www.njctl.org

page79svg

page194svg

page309svg

page47svg

page121svg

page71svg

page150svg

page158svg

page46svg

page300svg

page65svg

page39svg

page23svg

http://www.corestandards.org/Math/Practice/#CCSS.Math.Practice.MP1

page1svg

page20svg

page35svg

page45svg

page48svg

page0svg

page130svg

page0svg

Slide 6 (Answer) / 291

Mentally Adding 10


[This object is a pull tab]

Teac

her N

otes

[This object is a teacher notes pull tab]

In this lesson you will review counting by tens,

and practice adding ten mentally Sample Text

Slide 7 / 291

Count by 10s

Slide 8 / 291

Write the numbers

What digit is changing as you count?

Slide 9 / 291

Write the Numbers

What pattern do you see?

Does that last number follow the same pattern?

Slide 10 / 291

What number is this?

Add ten more and what number does it become?



Add ten more and what number does it become?


Teac

her N

otes

The long at the bottom is cloned to allow the students

to drag 10 more and recount.

page0svg

Slide 11 / 291


Add ten more and what number does it become?What happened to the tens place when you added

10 more?



Add ten more and what number does it become?What happened to the tens place when you added

10 more?


Teac

her N

otes



Slide 12 / 291

Adding 10

Add ten more and what number does it become?What happened to the tens place when you added 10 more?

What happened to the ones place when you added 10 more?


Adding 10




Teac

her N

otes



Slide 13 / 291

Adding 10




Adding 10




Teac

her N

otes



Slide 14 / 291

What number comes next?

Count by 10s

34, 44, ___, ___, ___, ___

Slide 15 / 291

Adding 10What number is this?

Add 10 more.What happened in each place when you added 10?





Teac

her N

otes



Slide 16 / 291







Teac

her N

otes



Slide 17 / 291







Teac

her N

otes



Slide 18 / 291







Teac

her N

otes


to drag 10 more and recount. Take time on this page to discuss that if the tens place has 9 tens and you add another 10, the

hundreds has to change too. Ask the students why?

Slide 19 / 291







Teac

her N

otes


to drag 10 more and recount. Take time on this page to discuss that if the tens place has 9 tens and you add another 10, the

hundreds has to change too. Ask the students why?

Slide 20 / 291


Count by 10s

340, 350, ___, ___, ___, ___



Count by 10s

340, 350, ___, ___, ___, ___


___Te

ache

r Not

es

Review when counting by 10s, once you count up to the digit 9 in the tens place, the hundreds place changes by going up one and the tens place returns to 0. Remind

students that the ones place NEVER changes when

counting by tens.

Slide 21 / 291


Count by 10s

648, 658, ___, ___, ___, ___

Teac

her N

otes

Slide 22 / 291

110 + 10 = 120

Adding 10


110 + 10 = 120

Adding 10


Teac

her N

otes

Point out to students that when you add ten in an

addition sentence only the tens place changes. Ask if they know of a time when

the tens and hundreds would change.

Slide 23 / 291

What number is 10 more?

247

493162530

781333

Slide 24 / 291

1 Is 10 more than 567 577?

Yes

No


1 Is 10 more than 567 577?

Yes

No


Ans

wer

Yes

Slide 25 / 291

2 Is 10 more than 142 153?

Yes

No


2 Is 10 more than 142 153?

Yes

No


Ans

wer

No

Slide 26 / 291

3 What is 10 more than this number?




Ans

wer

520

Slide 27 / 291





Ans

wer

92

Slide 28 / 291

5 73 + 10 = ?


5 73 + 10 = ?


Ans

wer

83

Slide 29 / 291

Slide 30 / 291 Slide 31 / 291



page0svg





Teac

her N

otes

This lesson focuses onreviewing counting back 10

and practicing mentally subtracting 10.

Slide 32 / 291

Count by 10

What pattern do you see in the numbers as you count?

Slide 33 / 291

Count by 10

Start on the left and count back by 10.

What pattern do you see in the numbers as you count back?

80

Slide 34 / 291

What number is shown?




Teac

her N

otes

Delete a ten and ask what number is now shown. Write each number on the board and ask students

what they notice (ones stay the same; digit in the tens

place is one less.)

Slide 35 / 291


What is 10 less?

page0svg



What is 10 less?


Teac

her N

otes



place is one less.)

Slide 36 / 291


What is 10 less?



What is 10 less?


Teac

her N

otes



place is one less.)

Slide 37 / 291

10 LessWhat number is this?

Take 10 away.What happened in each place?





Teac

her N

otes

Take the time to explain that the hundreds and the ones did not change. Since we

took 10 away the tens place is the only place that

changed.

Slide 38 / 291



Slide 39 / 291







Teac

her N

otes

Ask students how they can take 10 away if they don't have any tens. Allow them time to discuss ideas with a partner.

Explain that since 100 is made of 10 tens, they have to take a 10 away from the hundreds. This will make the hundreds place go down one and the

tens place to be a 9.

Slide 40 / 291



Slide 41 / 291



Slide 42 / 291

Count back by 10s.

180, 170, ___, ___, ___, ___, ___


Count back by 10s.

180, 170, ___, ___, ___, ___, ___


Teac

her N

otes

Review when counting back by 10s, once you count to the digit

0 in the tens place, the tens place will become a 9 and the hundreds place will be ONE LESS. Remind students that

the ones place NEVER changes when counting by

tens.

Slide 43 / 291

Count back by 10s.

260, 250, ___, ___, ___, ___, ___


Count back by 10s.

260, 250, ___, ___, ___, ___, ___


Mat

h Pr

actic

e

MP7 Look for and make use of structure.

Ask student what patterns they see when counting back by 10.

Slide 44 / 291

557, 547, ___, ___, ___, ___

Count back by 10s.

Slide 45 / 291

What number is 10 less?

631

148444290

525317

Slide 46 / 291

6 Is 10 less than 384 374?

Yes

No


6 Is 10 less than 384 374?

Yes

No


Ans

wer

Yes

Slide 47 / 291

7 What is 10 less than this number?




Ans

wer

143

Slide 48 / 291





Ans

wer

397

Slide 49 / 291

9 621 - 10 =


9 621 - 10 =


Ans

wer

611

Slide 50 / 291 Slide 51 / 291

Slide 52 / 291

Review Adding and Subtracting 10


Slide 53 / 291

When you add 10the tens place goes

UP one digit.152 + 10 = 162click for an example

Once you count up to9 in the tens place, that digit becomes a 0 and

the hundreds place goesup ONE digit. The onesplace stays the same.

294 + 10 = 304click for an example

Adding 10

Slide 54 / 291

When you subtract 10 the tens place

goes down one digit.385 - 10 = 375click for an example

609 - 10 = 599click for an example

Once you count down to 0 in the ones place, that digit

becomes a 9 and the hundreds place goes down ONE digit. The ones place

stays the same.

Subtracting 10

Slide 55 / 291

PracticeWhat number is this?

Take 10 away.

_______ - 10 = _______

page0svg

Slide 56 / 291


Add 10 more.

_______ + 10 = _______

Slide 57 / 291


Find 10 more and 10 less

_______ + 10 = _______

_______ - 10 = _______

Slide 58 / 291

Move the numbers into the correct place.

228

381

296

10 less

238

129

804

592

139

480

10 more

248

391

401

119

794

814

460

470

316

306

582

602

10 More 10 Less


Move the numbers into the correct place.

228

381

296

10 less

238

129

804

592

139

480

10 more

248

391

401

119

794

814

460

470

316

306

582

602

10 More 10 Less


Teac

her N

otes For this activity students

move the numbers into the correct column horizontally.

Slide 59 / 291

10 less10 more

Target Number

183173

266 256

304 294

482 492507 497

693 703

724 714

831 841

989 999

1005 995

10 more 10 less

10 more 10 less

10 more 10 less10 less10 more

10 more

10 more

10 more

10 more

10 more

10 less

10 less

10 less

10 less

10 less

10 More 10 Less


10 less10 more

Target Number

183173

266 256

304 294

482 492507 497

693 703

724 714

831 841

989 999

1005 995

10 more 10 less

10 more 10 less

10 more 10 less10 less10 more

10 more

10 more

10 more

10 more

10 more

10 less

10 less

10 less

10 less

10 less

10 More 10 Less


Teac

her N

otes For this activity, students need

to see if the number in thecircle is 10 more or 10 less

than the target number. They click on the box of their

answer.

Slide 60 / 291

When we add or subtract 10 to a number,what place value ALWAYS stays the same?

click each box for a question

When does the hundreds place change when adding 10?

When does the hundreds placechange when subtracting 10?

Slide 61 / 291

10 Is 346, 10 more or 10 less than 336?

A 10 more

B 10 less



A 10 more

B 10 less


Ans

wer

A

Slide 62 / 291


A 10 more

B 10 less



A 10 more

B 10 less


Ans

wer

No

Slide 63 / 291

12 What is 10 less than 518?




Ans

wer

508

Slide 64 / 291

13 What is 10 more than 96?




Ans

wer

106

Slide 65 / 291





Ans

wer

737

Slide 66 / 291





Ans

wer

195

Slide 67 / 291

Slide 68 / 291 Slide 69 / 291

Adding and Subtracting 100


Slide 70 / 291

Count by 100


Count by 100


Teac

her N

otes

Discuss the pattern in the 100s with the students. Ask them what they notice about

the tens and ones.

page0svg

Slide 71 / 291

Count by 100


Count by 100


Teac

her N

otes

Discuss the pattern in the 100s with the students. Ask them what they notice about

the tens and ones.

Slide 72 / 291

What number does this show?




Teac

her N

otes

After the correct answeris given, write it on the first line. Then pull down the

bottom hundred (it is cloned) and ask again what number is shown. Discuss how the number changed when we

added 100.

Slide 73 / 291

326 + 100 = 426

What place value changed when 100 was added?

How did it change?

Adding 100


326 + 100 = 426

What place value changed when 100 was added?

How did it change?

Adding 100


Teac

her N

otes Encourage students to

recognize that the hundredsplace changed by goingup one digit, but the tensand ones places did not.

Slide 74 / 291


______ + 100 = ______



______ + 100 = ______


Teac

her N

otes



added 100. Write the answer on the last line.

Slide 75 / 291


______ + 100 = ______



______ + 100 = ______


Teac

her N

otes



added 100. Write the answer on the last line.

Slide 76 / 291





Teac

her N

otes

After the correct answeris given, write it on the first

line. Then click on the bottom hundred (it will

fade out) and ask again what number is shown. Write the number on the

line.

Slide 77 / 291

547 - 100 = 447

What place value changed when 100 was subtracted?

How did it change?

Subtracting 100


547 - 100 = 447

What place value changed when 100 was subtracted?

How did it change?

Subtracting 100


Teac

her N

otes Encourage students to

recognize that the hundredsplace changed by going

down one digit, but the tensand ones places did not.

Slide 78 / 291


______ - 100 = ______



______ - 100 = ______


Teac

her N

otes




line.

Slide 79 / 291


______ - 100 = ______



______ - 100 = ______


Teac

her N

otes




line.

Slide 80 / 291

What will happenif I add one more?

How many hundreds are here?

Adding 100


What will happenif I add one more?

How many hundreds are here?

Adding 100


Teac

her N

otes Show students this concept,

although it is not somethingthey need to know at this point.

This lesson only focuses on adding and subtracting within

900.

Slide 81 / 291

10 hundreds is the same as 1 thousand or 1,000.

Adding & Subtracting 100

Slide 82 / 291

When 100 is added or subtracted the tens and ones places stay the same.

If 100 is added, how doesthe hundreds place

change?

If 100 is subtracted, how doesthe hundreds place change?

click

click



When 100 is added or subtracted the tens and ones places stay the same.

If 100 is added, how doesthe hundreds place

change?

If 100 is subtracted, how doesthe hundreds place change?

click

click



Teac

her N

otes

Let students know that fornow they don't have to

worry about the hundreds place changing at all.

Slide 83 / 291

16 100 more than 592 is 692.

True

False


16 100 more than 592 is 692.

True

False


Ans

wer

True

Slide 84 / 291

17 100 less than 364 is 354.

True

False


17 100 less than 364 is 354.

True

False


Ans

wer

False

Slide 85 / 291





Ans

wer

781

Slide 86 / 291





Ans

wer

194

Slide 87 / 291





Ans

wer

227

Slide 88 / 291





Ans

wer

823

Slide 89 / 291

Slide 90 / 291 Slide 91 / 291

Review Adding and Subtracting 10 and 100


Slide 92 / 291

When adding or subtracting 100, what place value stays the same?

What place value or values change when adding or subtracting 100?

When adding or subtracting 10,what place value stays the same?

When adding or subtracting 10,what place value or values changes

and when?

click each box for a question

Slide 93 / 291

Use the base 10 blocks to show 10 more than 372


Use the base 10 blocks to show 10 more than 372


Teac

her N

otes Base 10 blocks are infinitely

cloned to help students make the numbers. Have

students make the numbers on their own.

Slide 94 / 291

Use the base 10 blocks toshow 10 more than 594

page0svg




Mat

h Pr

actic

e

MP5 Use appropriate tools strategically.

Have students practice making the numbers on their desk with

base ten blocks before showing the work on the board.

Slide 95 / 291

Use the base 10 blocks toshow 10 less than 403

Slide 96 / 291


Slide 97 / 291


Slide 98 / 291


Slide 99 / 291


Slide 100 / 291


Slide 101 / 291

100 Less 10 Less Target

Number 10 More 100 More

338 428 438 448 538

527

175

396

651

Adding & Subtracting 10 and 100

Teac

her N

otes

&

Mat

h Pr

actic

e

Slide 102 / 291





Ans

wer

139

Slide 103 / 291





Ans

wer

716

Slide 104 / 291





Ans

wer

519

Slide 105 / 291


Quiz



Quiz[This object is a pull tab]

Ans

wer

124

Slide 106 / 291

Lab: Carpet Square Math

Take turns flicking a bottle cap from a launching square toward the center and then add the numbers for the

region landed on to obtain a score. Bumping is permitted!

Click here for complete directions


Slide 107 / 291

http://www.raftbayarea.org/readpdf?isid=602

page0svg

Slide 108 / 291 Slide 109 / 291

click to go to the section

Addition2 Digit Addition with Number GridAddition with Base 10 Blocks2 Digit Addition

2 Digit Addition with Regrouping

Adding 3 and 4 2-Digit numbersClick to return to Table of Contents

Lab: Thirty One

Lab: Bottle Bowling

Problem Solving with Addition

2 Digit Addition with Regrouping Part 2

Problem Solving with AdditionAddition into Hundreds with RegroupingTwo Digit Addition Review

Slide 110 / 291

click to return toaddition table of contents

2 Digit Additionwith Number Grid



2 Digit Additionwith Number Grid


Teac

her N

otes

This lesson focuses on beginning to add 2 digit

numbers, without regrouping. The strategy taught in this lesson

is to add with a number grid, showing how to add 10 by going down and counting over. Prior to

the lesson, hand out number grids and counters to each

student. They may also use their number grids to answer the

questions.

Slide 111 / 291

How can we use the

number grid to solve this

problem?

There were 52 green apples in the basketand 31 red apples.

How many apples were there all together?

Adding on a Number Grid


How can we use the

number grid to solve this

problem?

There were 52 green apples in the basketand 31 red apples.

How many apples were there all together?



Teac

her N

otes

Lead students to use the circle to begin at the larger number (52) and count up 31 to get the answer. Ask if they can think of an easier way to count on the grid for

these bigger numbers.

page80svg

page92svg

page101svg

page129svg

page208svg

page0svg

page57svg

page118svg

page116svg

page141svg

page157svg

page169svg

page181svg

page79svg

page79svg

Slide 112 / 291

When adding larger numbers on the grid, start with the larger number. Count by tens, then ones.

52 + 31

How many tens are in 31?




52 + 31

How many tens are in 31?



Teac

her N

otes

When students answer that there are 3 tens in 31, show

how you move the circle down 3 spaces, counting by tens as you do. Ask how many more they need to count to make

31...then move 1 space to the right. Explain to students that when you count by 10s, you

move down the grid and when you count by ones, you move

over to the right.

Slide 113 / 291

41 + 18




41 + 18




Teac

her N

otes

The following pages you will be practicing adding larger

numbers on the number grid. Remind students to

count by tens first by moving down spaces, then count

ones. Always start with the larger number. Have

students practice along with their own number grids.

Slide 114 / 291

23 + 34 =



Slide 115 / 291

62 + 35



Slide 116 / 291

26 85 + 14 =

A 98

B 99

C 89

D 95

* Use your number grid at your seats to help you. *


26 85 + 14 =

A 98

B 99

C 89

D 95



Ans

wer

B

Slide 117 / 291

27 54 + 22

A 74

B 72

C 76

D 34



27 54 + 22

A 74

B 72

C 76

D 34

* Use your number grid at your seats to help you. *[This object is a pull tab]

Ans

wer

C

Slide 118 / 291

28

7313

+



28

7313

+



Ans

wer

86

Slide 119 / 291

29

2421

+



29

2421

+

* Use your number grid at your seats to help you. *[This object is a pull tab]

Ans

wer

45

Slide 120 / 291

30 21 + 47 =



30 21 + 47 =



Ans

wer

68

Slide 121 / 291 Slide 122 / 291

Slide 123 / 291

Addition with Base 10 Blocks



Addition with Base 10 Blocks



Teac

her N

otes

In this lesson you will be showing students how to

use base 10 blocks to solve addition problems.

Use base 10 manipulatives to help students with the

concept. Hand out prior to the lesson and review the

value for each block.

Slide 124 / 291

Tens Ones

35 + 23 =

Adding with Base Ten Blocks


Tens Ones

35 + 23 =



Teac

her N

otes

Use the base 10 blocks (they are infinitely cloned) to show each

number. Circle the ones and write the number in the ones column,

then circle the tens and write in the tens column. Have students do this with base 10 blocks at their seats.

On the following pages, have students practice making the ones and tens, circling them, and then

writing the total in the box.

Slide 125 / 291

Tens Ones

17 + 42


Slide 126 / 291

Tens Ones

58 + 40 =


page79svg

page79svg

Slide 127 / 291

Tens Ones

26+ 31

Adding with Base Ten BlocksSlide 128 / 291

Tens Ones

43+ 5


Slide 129 / 291

31 62 + 36 =


31 62 + 36 =


Ans

wer

98

Slide 130 / 291

32

73+ 11


32

73+ 11


Ans

wer

84

Slide 131 / 291

33 84 + 15 =


33 84 + 15 =


Ans

wer

99

Slide 132 / 291

34

33+ 46


34

33+ 46

[This object is a pull tab]A

nsw

er 79

Slide 133 / 291

35 24 + 70 =


35 24 + 70 =


Ans

wer

94

Slide 134 / 291 Slide 135 / 291

Slide 136 / 291

2 Digit Addition



2 Digit Addition



Teac

her N

otes

This lesson will focus on adding 2 digit addends using paper and pencil method. Students will be encouraged to use their mental math skills to add the ones first,

then the tens. Encourage students to remember their easy addition

facts to help them add. Struggling students may use a number line, number grid, or their fingers as strategies. Supply students with

scrap paper to work out problems.

Slide 137 / 291

6 532+

Tens Ones6 53 2+

The ones must be lined upand the tens must be lined up.

When adding 2 digit addends it is VERY IMPORTANT to line up your addends correctly!!

65 + 32 =

Lining Up Addends


6 532+

Tens Ones6 53 2+

The ones must be lined upand the tens must be lined up.

When adding 2 digit addends it is VERY IMPORTANT to line up your addends correctly!!

65 + 32 =

Lining Up Addends


Teac

her N

otes

Show students how the onesand tens are lined up right

under each other. Also, pointout where the plus sign is.

Have students copy this on theirscrap paper to ensure they are

writing the problem correctly.

page79svg

page79svg

Slide 138 / 291

Lining Up Addends

Are these number lined up correctly?

56

+ 23 72

+ 63 12

+ 45


Lining Up Addends

Are these number lined up correctly?

56

+ 23 72

+ 63 12

+ 45


Teac

her N

otes

MP 3 Construct viable arguments and critique the reasoning of

others.

Have students look at each problem in a small group and

discuss if they think it is lined up correctly or not. Allow them time to

critique each other in a friendly manner. Then discuss each

problem as a class.

Slide 139 / 291

Once the problem is lined up correctly, add the ones column first.

Tens Ones

6 53 2+

Lining Up Addends

Be sure to write the sum of the ones directly under the ones.

Slide 140 / 291

After you add the ones, add the tens column.

Tens Ones

6 53 2+

7

Lining Up Addends

Be sure to write the sum of the tens directly under the tens.

Slide 141 / 291

6532+

79

Lining Up Addends

Slide 142 / 291

Tens Ones+2

Practice

6 5 3


Tens Ones+2

Practice

6 5 3


Teac

her N

otes

The numbers are separate. Pull each number into the tens and ones chart to show how to line up the numbers correctly. Circle the ones and add. Then

circle the tens and add.

Slide 143 / 291

Tens Ones+6

Practice

1 1 6


Tens Ones+6

Practice

1 1 6


Teac

her N

otes

The numbers are separate. Pull each number into the tens and ones chart to show how to line up the numbers correctly. Circle the ones and add. Then


Slide 144 / 291

Practice

44

62+

Tens Ones


Practice

44

62+

Tens Ones


Teac

her N

otes The numbers are separate.

Pull each number into the tens and ones chart to show how to line up the numbers correctly. Circle the ones and add. Then


Slide 145 / 291

Practice

7 45 +Tens Ones

What is different with this problem?


Practice

7 45 +Tens Ones

What is different with this problem?


Teac

her N

otes

Have students identify that there is only 1 digit in the

second addend. Ask if that number will go in the tens or ones. Once they line up the

numbers correctly, lightly draw a 0 in the tens next to the 4 to show the students

that there is 0 in the tens for that number.

Slide 146 / 291

Add without using the tens and ones chart.

61+ 22



61+ 22


Teac

her N

otes You may wish to show

students how to draw a line between the tens and the

ones to help keep the numbers lined up.

Slide 147 / 291

11 + 31 =



11 + 31 =



Teac

her N

otes

Have students rewrite the numbers and then add.

Slide 148 / 291

36 26 + 71 =


36 26 + 71 =


Ans

wer

97

Slide 149 / 291

37

84+ 12


37

84+ 12


Ans

wer

96

Slide 150 / 291

38

25+ 23


38

25+ 23


Ans

wer

48

Slide 151 / 291

39 34 + 54 =


39 34 + 54 =


Ans

wer

88

Slide 152 / 291

40 15 + 34 =


40 15 + 34 =


Ans

wer

49

Slide 153 / 291

Slide 154 / 291 Slide 155 / 291

Problem Solving

with Addition


page0svg


Problem Solving

with Addition



Teac

her N

otes For this lessons,supply

students with scrap paper and base 10 blocks to help solvethe word problems.

Slide 156 / 291

Jim has 3 pennies.

His mom gives him 2 more.

How many pennies does Jim have in all?

Underline what we know.

Circle what we want to know.

=+

Word Problem


Jim has 3 pennies.

His mom gives him 2 more.

How many pennies does Jim have in all?



=+

Word Problem

Teac

her N

otes

[This object is a teacher notes pull tab]

Read the entire story and then underline the first two lines to show that this is the information we KNOW.

The circle the last line to show that this is what we want to know. Point out the question mark at the end and

remind the students that this tells us that they are asking us something.

Next, guide the students to write an addition sentence to solve the problem.

Have them go back and check that their sentence matches the story and that the addition sentence makes sense (the sum must be larger than the

addends).

Slide 157 / 291

When looking at a word problem, we first need to figure out if the numbers we know show the whole

number of things or the parts.

Word Problems

Rob picked 17 blueberries and 12 strawberries. How many berries did Rob pick?

Underline the parts.

Circle the whole.

Slide 158 / 291

Word Problems

What numbers will go in the chart?

Rob picked 17 blueberries and 12 strawberries. How many berries did Rob pick?

_____ berriesTens Ones

Slide 159 / 291

Will read 6 pages of hisbook on Monday. On Tuesday,

he read double the amountof pages. How many pages

did he read in all?

_____ pages

Word Problems

Tens Ones


Circle the whole.

page0svg


Will read 6 pages of hisbook on Monday. On Tuesday,

he read double the amountof pages. How many pages

did he read in all?

_____ pages

Word Problems

Tens Ones


Circle the whole.


Teac

her N

otes For this problem, students

need to think first, whatis double 6 before they can

add the 2 numbers.

Slide 160 / 291

Jake planted 22 tomato plantsin his front yard and 16 in hisbackyard. How many tomatoplants did Jake plant in all?

_____ plants

Word Problems

Tens Ones


Circle the whole.

Slide 161 / 291

Nathan saved 65 cents. This week he will save 12 cents. How much money will he have then?

_____ cents

Word Problems

Tens Ones

Slide 162 / 291

41 James buys two coupon books. Each book has 24 coupons. How many coupons does he buy?

A 22

B 24

C 44

D 48


41 James buys two coupon books. Each book has 24 coupons. How many coupons does he buy?

A 22

B 24

C 44

D 48


Ans

wer

D

Slide 163 / 291

42 Which is the sum?

22 + 61 =

A 41

B 68

C 83

D 74


42 Which is the sum?

22 + 61 =

A 41

B 68

C 83

D 74


Ans

wer

C

Slide 164 / 291

43 Ms. Johnson's class has a fish tank with 15 red fish and 24 black fish. How many fish are in the tank?


43 Ms. Johnson's class has a fish tank with 15 red fish and 24 black fish. How many fish are in the tank?


Ans

wer

39

Slide 165 / 291

44 The soccer team sold 38 white shirts and 50 blue shirts. How many shirts did they sell in all?


44 The soccer team sold 38 white shirts and 50 blue shirts. How many shirts did they sell in all?


Ans

wer

88

Slide 166 / 291

45 In Mr. Smith's class there are 7 girls and 12 boys. How many children are in Mr. Smith's class?

Quiz

A 5

B 82

C 19

D 91


45 In Mr. Smith's class there are 7 girls and 12 boys. How many children are in Mr. Smith's class?

Quiz

A 5

B 82

C 19

D 91


Ans

wer

C

Slide 167 / 291

Slide 168 / 291 Slide 169 / 291







Teac

her N

otes

This lesson serves as an introduction to regrouping using base 10 blocks. Use the base 10 blocks to show

how there are too many ones to keep in the ones

place, so they need to trade in for a ten. Supply students with base 10 blocks to use

for the lesson and the questions.

Slide 170 / 291

36 + 27 =

Tens

Ones

Addition with Regrouping

page79svg

page79svg


36 + 27 =

Tens

Ones



Teac

her N

otes

Explain to students that we want to add these two numbers together.

First, have them count all the ones. When they come up with the answer 13, remind students that only ONE digit can fill in a place value. Since

we have 13 cubes, we need to trade 10 of them in for a long. Demonstrate that by circling 10 cubes, then delete

them and bring in a long from the box. Show now that there are 6 tens

and 3 ones so the answer is 63.

Slide 171 / 291

Tens Ones

46 + 29 =Practice


Tens Ones

46 + 29 =Practice


Teac

her N

otes

On the following pages there are practice questions with

base 10 blocks. Have students make the numbers with their

own base 10 blocks and on the board. When the ones are

added, remind students that if the answer is 2 digits, they

have to trade 10 ones for a ten. Practice trading in 10 cubes for one 10 - then adding the ones

first then the tens.

Slide 172 / 291

Tens Ones

Practice

72 + 19

Slide 173 / 291

Tens Ones

Practice

17 + 23 =

Slide 174 / 291

Tens Ones

Practice

25 + 47

Slide 175 / 291

Tens Ones

Practice

34 + 16

Sometimes you may not have base ten blocks to help you. What could you do?


Tens Ones

Practice

34 + 16

Sometimes you may not have base ten blocks to help you. What could you do?


Teac

her N

otes

Allow students time to share their ideas. Then demonstrate

how to draw a line for a ten and a square for a 1. Then

talk through this problem aloud to demonstrate drawing the

blocks to find the sum.

Slide 176 / 291

Practice

28 + 37

Draw base-ten blocks to help you solve this problem.

Slide 177 / 291

Practice

84 + 9

Draw base-ten blocks to help you solve this problem.

What digit is here?

Slide 178 / 291

Change the columns to 2 prior to starting

Click on the picture below for more practice on the National Library of Virtual Manipulatives site.

Slide 179 / 291

46 32 + 59 =

http://nlvm.usu.edu/en/nav/frames_asid_154_g_1_t_1.html?from=category_g_1_t_1.html


46 32 + 59 =


Ans

wer

91

Slide 180 / 291

47

37+ 48


47

37+ 48


Ans

wer

85

Slide 181 / 291

48 58 + 18 =


48 58 + 18 =


Ans

wer

76

Slide 182 / 291

49

27+ 14


49

27+ 14


Ans

wer

41

Slide 183 / 291

50 47 + 43 =


50 47 + 43 =


Ans

wer

90

Slide 184 / 291

Slide 185 / 291 Slide 186 / 291

Regrouping without Manipulatives


page0svg


Regrouping without Manipulatives



This lesson focuses on 2 digit addition with

regrouping without using base 10 blocks. Supply

students with paper to work out the problems on their

own throughout the lesson.

Slide 187 / 291

tens ones

2 52 8+

Add the ones first

5 + 8 =


Slide 188 / 291

tens ones

2 52 8+

5 + 8 =

tens ones

1 3



tens ones

2 52 8+

5 + 8 =

tens ones

1 3



Teac

her N

otes Explain that the one has to

go in the ones column and the ten has to go in the

tens column. The numbers are separate to allow you

to move them to the correct spot.

Slide 189 / 291

tens ones

2 52 8+

1

3

Now addthese 3 numbers


Slide 190 / 291

tens ones

2 52 8+

1

35


page0svg

Slide 191 / 291

tens ones

4 21 9+

Let's Practice

Which numbers do we add first?

Slide 192 / 291

tens ones

4 21 9+

1 Now what dowe do?

1

Let's Practice

Slide 193 / 291

If the problem is written horizontally, rewrite it vertically to

make it easier to add.

tens ones

+

3 6 + 1 8

Let's Practice


If the problem is written horizontally, rewrite it vertically to

make it easier to add.

tens ones

+

3 6 + 1 8

Let's Practice


Teac

her N

otes The numbers are separate

to move into the chart. Remind students to line up the numbers correctly to

avoid mistakes.

Slide 194 / 291

29+ 44

Let's Practice

Slide 195 / 291

18 + 52 =

Let's Practice


18 + 52 =

Let's Practice


Mat

h Pr

actic

e

MP 1 Make sense of problems and persevere in solving them

Ask students how they would start this problem. They should start by lining up the numbers. Ask what tools they could use if

they got stuck.

Slide 196 / 291

+Roll all 4 dice and then add the numbers.

Slide 197 / 291

51 57 + 38 =


51 57 + 38 =


nsw

er

95

Slide 198 / 291

52

49+ 24


52

49+ 24


Ans

wer

73

Slide 199 / 291

53

56+ 28


53

56+ 28


Ans

wer

84

Slide 200 / 291

54 48 + 26 =


54 48 + 26 =


Ans

wer

74

Slide 201 / 291

55

39+ 33


55

39+ 33


Ans

wer

72

Slide 202 / 291

Lab: Bottle Bowling


This RAFT version of a classic game uses plastic bottles as bowling pins and a small wooden ball. It plays just like

the bowling alley game, but instead of a computer keeping score, the individual players must keep track of

their points. Scoring gets a bit tricky when a strike or spare is rolled, providing excellent opportunity to practice

basic arithmetic.


Slide 203 / 291

Slide 204 / 291 Slide 205 / 291

Problem Solving

with Addition



Problem Solving

with Addition



Teac

her N

otes

Supply students with scrap paper to solve the word

problems. Remind students that only when they add the ones

and the sum is a 2 digit number, do they have to regroup.

Slide 206 / 291

How do we addthese numbers?

tens ones

1 61 8+

16 boys ride their bikes to school.18 girls ride their bikes to school.How many bikes are ridden to school?

Word Problems


page0svg

page0svg

page0svg

Slide 207 / 291

tens ones

+

Rich reads 26 pages. Mike reads 37 pages.How many pages did Rich and Mike read in all?

Word Problems

Slide 208 / 291

tens ones

+

24 frogs in the water. 43 frogs hopping on land. How many frogs in all?

Why don't we haveto regroup for this

problem?

Word Problems

Slide 209 / 291

Taylor counts 46 stars.Morgan counts 39 stars.

How many stars did they count?

Word Problems

Slide 210 / 291

Liam has 29 golf balls.Ryan has 43 golf balls.

How many golf balls do they have?

Word Problems


Liam has 29 golf balls.Ryan has 43 golf balls.

How many golf balls do they have?

Word Problems


Mat

h Pr

actic

e

MP 2 Make sense of problems and persevere in solving them.

How can you represent the problem with symbols and

numbers? What does each number represent?

Slide 211 / 291

56 Tracy ran in 26 races. Kaylee ran in 14 races. How many races did they run?

A 30

B 31

C 41

D 40


56 Tracy ran in 26 races. Kaylee ran in 14 races. How many races did they run?

A 30

B 31

C 41

D 40


Ans

wer

D

Slide 212 / 291

57 There are 44 rows of corn in a field. There are 53 rows of corn in another field. How many rows of corn in all?

A 98

B 97

C 107

D 87


57 There are 44 rows of corn in a field. There are 53 rows of corn in another field. How many rows of corn in all?

A 98

B 97

C 107

D 87


Ans

wer

B

Slide 213 / 291

58 Steve sees 36 birds. Jack sees 28 birds. How many birds do they see?


58 Steve sees 36 birds. Jack sees 28 birds. How many birds do they see?


Ans

wer

64

Slide 214 / 291

59 Tim has 63 nickels. Olivia has 29 nickels. How many nickels do they have?


59 Tim has 63 nickels. Olivia has 29 nickels. How many nickels do they have?


Ans

wer

92

Slide 215 / 291

60 Debbie sees 48 monkeys at the zoo. Brenda sees 35 different monkeys. How many monkeys did they see?


60 Debbie sees 48 monkeys at the zoo. Brenda sees 35 different monkeys. How many monkeys did they see?


Ans

wer

83

Slide 216 / 291

61 There are 46 daisies and 35 sunflowers in the garden. How many flowers are there in all?


61 There are 46 daisies and 35 sunflowers in the garden. How many flowers are there in all?


Ans

wer

81

Slide 217 / 291

Slide 218 / 291 Slide 219 / 291

Addition into the Hundreds

with Regrouping



Addition into the Hundreds

with Regrouping



Teac

her N

otes This lesson focuses on

adding 2 digit numbers and regrouping into the hundreds place. Supply students with scrap paper to work out the

problems.

Slide 220 / 291

How many ones?

Add:63 + 52

How many tens?

Addition into Hundreds

Slide 221 / 291

Add:63 + 52

11 tens 5 ones =


Slide 222 / 291

What can we tradethese 10 longs for?

Add:63 + 52


page0svg

page0svg

Slide 223 / 291


Add:63 + 52

When you add the tens placeand the answer is a 2 digit sum,you must trade in for a hundred.


Slide 224 / 291

How do we know if we have to regroup?

+

H T O

6 35 2

1. Always add the ones first.

2. Ask: Do I regroup?

Do we have to regroup?


Slide 225 / 291

+

H T O

6 35 2

1. Always add the ones first.2. Ask: Do I regroup?3. Add the tens.4. Ask: Do I regroup?

5 Do we have to regroup?


Slide 226 / 291

+

H T O

6 35 2

6 + 5 = To regroup from the tens place into the hundreds:

Look at the sum of the tens place.The digit in the ones place goes in the tens column. The digit in the tens place is regrouped into the

hundreds column.

1 1


5


+

H T O

6 35 2

6 + 5 = To regroup from the tens place into the hundreds:

Look at the sum of the tens place.The digit in the ones place goes in the tens column. The digit in the tens place is regrouped into the

hundreds column.

1 1


5 [This object is a pull tab]

5

Teac

her N

otes

The digits in the 11 are separate to demonstrate

putting the ones place in the tens column and carrying

the other one into the hundreds column.

Slide 227 / 291

+

H T O

6 35 2

1

1 5

Now add the hundreds place.



+

H T O

6 35 2

1

1 5

Now add the hundreds place.



5

Teac

her N

otes

Explain that because there is only a one in the

hundreds place they are really adding that one to a zero. If there are no other

digits in the hundreds column, that represents

zero.

Slide 228 / 291

+

H T O

6 35 2

5

1

1 1


Slide 229 / 291

+

H T O

5 78 4

1. Always add the ones first.2. Ask: Do I regroup?3. Add the tens.4. Ask: Do I regroup?5. Add the hundreds.



+

H T O

5 78 4




Teac

her N

otes

The following pages work through each step of an addition problem when

regrouping is necessary in both the ones and tens columns. The sums are in red and are

moveable to slide into the correct position as

you work through the problem.

Slide 230 / 291


+

H T O

5 78 4

4 + 7 = 11


Slide 231 / 291


+

H T O

5 78 41

1

1 + 8 + 5 =


Slide 232 / 291


+

H T O

5 78 41

1

1 + 8 + 5 = 14Addition into Hundreds

Slide 233 / 291

+

H T O

5 78 4

1

1

1

4

1 + 0 =



Slide 234 / 291


+

H T O

7 79 0


Slide 235 / 291

+

H T O

4 5 6 4+1. Always add the ones first.2. Ask: Do I regroup?3. Add the tens.4. Ask: Do I regroup?5. Add the hundreds.



+

H T O

4 5 6 4+1. Always add the ones first.2. Ask: Do I regroup?3. Add the tens.4. Ask: Do I regroup?5. Add the hundreds.



Teac

her N

otes

Remind students that when a problem is written

horizontally, it is much easier to rewrite the problem

vertically to solve it. These numbers are separate, so

they can be moved into the chart.

Slide 236 / 291

+

H T O7 3 8 6+




+

H T O7 3 8 6+




Teac

her N

otes





Slide 237 / 291

+

H T O2 8 7 4+



+

H T O2 8 7 4+



Teac

her N

otes





Slide 238 / 291

62

99+ 40

A 59B 109

C 149

D 139


62

99+ 40

A 59B 109

C 149

D 139[This object is a pull tab]

Ans

wer

D

Slide 239 / 291

63 86 + 36 =

A 102

B 122

C 112

D 132


63 86 + 36 =

A 102

B 122

C 112

D 132


Ans

wer

B

Slide 240 / 291

64 71 + 68 =


64 71 + 68 =


Ans

wer

139

Slide 241 / 291

65

59+ 32


65

59+ 32


Ans

wer

91

Slide 242 / 291

66

85+ 88


66

85+ 88


Ans

wer

173

Slide 243 / 291

Slide 244 / 291 Slide 245 / 291

Review 2 Digit Addition



Review 2 Digit Addition



Teac

her N

otes

This lesson is a review of 2 digit addition problems:

without regrouping, regrouping into the

tens, and regrouping into the hundreds. Supply students

with scrap paper to work out problems.

Slide 246 / 291

What do we know? What do we want to know?

There are 34 people on the train.27 more people get on.

How many people are on the train now?

Word Problems

+

H T O

page0svg

page0svg


What do we know? What do we want to know?

There are 34 people on the train.27 more people get on.

How many people are on the train now?

Word Problems

+

H T O


Teac

her N

otes

Remind students to:



Slide 247 / 291

3 4 2 7+

H T O1. Always add the ones first.2. Ask: Do I regroup?3. Add the tens.4. Ask: Do I regroup?5. Add the hundreds.

Review

Slide 248 / 291

Jeff's team scored 84 points.Marc's team scored 68 points.

How many points did they scoreall together?

Review

+

H T O

Slide 249 / 291

Shelby had 32 dollars.Jasmine had 57 dollars.

How many dollars did theyhave all together?

Review

Slide 250 / 291

Angelo put 63 nails in the board,then he put 44 more nails in the board.

How many nails did he put in all together?

ReviewSlide 251 / 291

67 Maria sold 47 tickets. Roger sold 23 tickets. How many tickets did they sell all together?

A 60

B 24

C 70

D 160


67 Maria sold 47 tickets. Roger sold 23 tickets. How many tickets did they sell all together?

A 60

B 24

C 70

D 160


Ans

wer

C

Slide 252 / 291

68 There are 72 red roses and 65 pink roses. How many roses all together?

A 137

B 147

C 37

D 127


68 There are 72 red roses and 65 pink roses. How many roses all together?

A 137

B 147

C 37

D 127


Ans

wer

A

Slide 253 / 291

69 Sophia had 56 stickers. She got 20 more. How many stickers does she have now?


69 Sophia had 56 stickers. She got 20 more. How many stickers does she have now?


Ans

wer

76

Slide 254 / 291

70 There were 75 bees were in the nests. 75 more flew in. How many are in the nest now?


70 There were 75 bees were in the nests. 75 more flew in. How many are in the nest now?


Ans

wer

150

Slide 255 / 291

71 Mrs. Field's room had 38 desks. Mrs. Scott's room had 15 desks. How many desks do they have all together?

Quiz


71 Mrs. Field's room had 38 desks. Mrs. Scott's room had 15 desks. How many desks do they have all together?

Quiz[This object is a pull tab]

Ans

wer

53

Slide 256 / 291

Slide 257 / 291 Slide 258 / 291

Adding 3 and 4 2-Digit Numbers


page79svg


Adding 3 and 4 2-Digit Numbers



Teac

her N

otes

The following lesson focuses on adding 3 and 4 2-digit addends. Review with students what they

learned in the previous unit about adding 3 numbers. Look for the easiest combination of

numbers to add first. With these problems they will again have to follow the regrouping rules also.

Supply students with scrap paper to work through problems.

Slide 259 / 291

+

H T O

4 21 53 4


Three and Four Addends


+

H T O

4 21 53 4




Teac

her N

otes

When ever they are adding more than 2 digits, ask the

students which 2 digits are the easiest to add first and why. Point out different tricks such as doubles, doubles +1, make

10, etc.

Slide 260 / 291

+

H T O

4 21 53 4

Where do you regroup to?

2 + 5 + 4 = 11



Slide 261 / 291

How many digitsam I adding?

+

H T O

4 21 53 4

1

1



Slide 262 / 291

+

H T O

4 21 53 4

1

1

1 + 4 + 1 + 3 = 91. Always add the ones first.2. Ask: Do I regroup?3. Add the tens.4. Ask: Do I regroup?5. Add the hundreds.


page79svg

Slide 263 / 291

+

H T O

3 42 31 4


Practice

Slide 264 / 291

+

H T O

7 22 11 6


Practice

Slide 265 / 291

+

H T O

4 75 68 2

Practice

Slide 266 / 291

1 36 84 5+

H T O

Practice

Slide 267 / 291

Click the random button three times to get three addends. After solving hit reset and get

three more.

_____ + _____ + _____ = _____

Practice


Click the random button three times to get three addends. After solving hit reset and get

three more.

_____ + _____ + _____ = _____

Practice


Teac

her N

otes

Have students solve the problem on their white boards

at their seats.

Slide 268 / 291

72 54 + 3 + 15 =

A 99

B 619

C 72

D 585


72 54 + 3 + 15 =

A 99

B 619

C 72

D 585


Ans

wer

C

Slide 269 / 291

73 42 93+ 37

A 170

B 162

C 172

D 1512


73 42 93+ 37

A 170

B 162

C 172


Ans

wer

C

Slide 270 / 291

74 45 + 13 + 29 =


74 45 + 13 + 29 =


Ans

wer

87

Slide 271 / 291

75

32 46+ 21


75

32 46+ 21


Ans

wer

99

Slide 272 / 291

76

84 9+ 76


76

84 9+ 76


nsw

er

169

Slide 273 / 291

Lab: Thirty One

This card game helps students learn to add numbers in their heads. The objective of the game is to get as close to 31 with any number of cards, without going over 31.



Slide 274 / 291


page0svg

Slide 275 / 291 Slide 276 / 291

More Adding 3 and 4 2-Digit Numbers


Slide 277 / 291

1 23 4

2 16

+

H T O


Practice


1 23 4

2 16

+

H T O


Practice


Teac

her N

otes

Work through the examples with the

students adding 4 2-digit addends. Students will

need to add up to 5 addends at a time to get the answer. Supply them with scrap paper to work

out the problems.

Slide 278 / 291

1 23 4

2 16

2 + 4 + 6 + 1 =

+

H T O

31Practice


Slide 279 / 291

1 23 4

2 16

1

3+

H T O

Practice


page79svg

Slide 280 / 291

1 23 4

2 16

1

3

1 + 1 + 3 + 2 = 7

+

H T O

Practice


Slide 281 / 291

2 71 5

84 2

+

H T O

Practice

Slide 282 / 291

8 73 0

2 31 9

+

H T O

Practice

Slide 283 / 291

How do we line these numbers up?

9 4 6 7 2 4 8+ + +

+

H T O

Practice

Slide 284 / 291

How do we line these numbers up?

8 3 5 6 1 3 3 7+ + +

+

H T O

PracticeSlide 285 / 291

77

11 38 74+ 25


77

11 38 74+ 25


Ans

wer

138

Slide 286 / 291

78 31 + 15 + 20 + 2 =

A 68

B 86

C 347

D 50


78 31 + 15 + 20 + 2 =

A 68

B 86

C 347

D 50


Ans

wer

A

Slide 287 / 291

79 23 + 36 + 57 + 10 =


79 23 + 36 + 57 + 10 =


Ans

wer

126

Slide 288 / 291

80

17 24 50+ 41

A 87

B 82

C 132

D 142


80

17 24 50+ 41

A 87

B 82

C 132


Ans

wer

C

Slide 289 / 291

81

63 29 55+ 48

Quiz


81

63 29 55+ 48

Quiz


Ans

wer

195

Slide 290 / 291

Slide 291 / 291

Documents

2nd Grade - content.njctl.orgcontent.njctl.org/courses/math/2nd-grade/2-digit-addition-subtraction/2... · 2nd Grade Two Digit Addition and Subtraction 2015-12-03 Slide 3 / 291 click