Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 1 Grade 1 MAP 2 D...

Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 1

Grade 1 MAP2D

Trimester 2

Instructional Strategies

Regrouping in Addition

Aligned to the 1997

California Content Standards


Addition with Regrouping2 digits + 1 digit

• Write the 2 digits + 1 digit problem horizontally. • Students rewrite the problem in “working form”

while reading the problem aloud splitting the tens and ones in the two digit number.

Ex. 35+8=

“Three tens, five ones” 3 5

“Down and to the left plus eight ones” + 8

“Equals”IAATF Trimester 2

Addition with Regrouping 2 digits + 1 digit Page 1


Begin adding in the ones column.

3 1

+ 8

• Ask these questions:

“Is the sum greater than 9?”“Is the sum a two digit number?”

“Can the sum be split into tens and ones?”

3 1

+ 8

3 9

9

If NO, then write the

sum and bring down the tens.

IAATF Trimester 2



If the answer was YES, then REGROUP.

3 5

+ 8

• Orally split the sum into tens and ones while writing so the 1 ten is written FIRST and then the 3 ones.

1

Ex. 3 5

+ 8

3

13

“One tens three ones”

IAATF Trimester 2


“Is the sum greater than 9?”

“Is the sum a two digit number?”

“Can the sum be split into tens and ones?”


Add the tens column.13 5

+ 84 3

• Rewrite the sum with the digits “together.”13 5

+ 8 4 3

43

IAATF Trimester 2



Addition with Regrouping2 digits + 2 digits

• Rewrite the problem vertically while reading it aloud, splitting the tens and ones in both numbers.

Ex. 35+48=

“Three tens, five ones” 3 5“Down and to the left plus four tens eight ones” + 4 8“Equals”

IAATF Trimester 2



Add the ones column

• Ask these questions:

“Is the sum greater than 9?”“Is the sum a two digit number?”“Can you split the sum into tens and

ones?”

3 1 + 4 8

9

If NO, th

en write the

sum and add the tens

column.

IAATF Trimester 2



If the answer to these questions is YES, then REGROUP.

• Orally split the sum into tens and ones while writing each digit. Regroup and write the 1 ten FIRST, then write the 3 ones.

1 Ex. 3 5

+ 4 8 3

• Add the tens column. Add the 2 digits in the tens place from the problem first, then add the 1 ten that was regrouped. Orally chant.

13 5

+ 4 8 8 3

7“3 tens plus 4 tens equals 7 tens plus one more ten equals 8 tens.”

IAATF Trimester 2



Addition with Regrouping3 digits + 3 digits

• Follow the same procedures as in the previous slide

(2 digits + 2 digits) for regrouping into the tens column.• Ask the question:

“Is the sum (in the tens column) a two digit sum?”

1

Ex. 2 3 5

+ 3 4 8

8 3

If NO, th

en write the

sum and add the

hundreds column.

IAATF Trimester 2



If the answer is YES…

• Write the sum and write a “0” in the ones place and orally read the sum for the tens column.

12 7 5

+ 3 4 8 3

• Regroup by orally saying and regrouping the one hundred in the hundreds column first then writing the 2 tens in the tens column. Remember regroup into the hundreds column first.

“One hundred” 1 12 7 5

+ 3 4 8 “Two tens” 2 3

12 120 “One hundred twenty”

“4 tens plus 7 tens equals 11 tens plus 1 more ten equal 12 tens altogether. 12 tens is 120.”

IAATF Trimester 2



Add the hundreds column 1 1 2 7 5

+ 3 4 8 6 2 3

• Rewrite the sum with the digits “together”. 1 1 2 7 5

+ 3 4 8 6 2 3

623

IAATF Trimester 2


Copyright ©, Long Beach Unified School District. All rights reserved. - Grade 1 Grade 1 MAP 2 D...

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