# Grade 2 Math Adding Two Digit Numbers

adding two digit numbers without regrouping, how to teach addition of two-digit numbers, adding two-digit numbers with regrouping,

## Adding Two Digit Numbers

Two Digit Numbers:

The numbers from 10 to 99 (ten to ninety-nine) are two-digit numbers.

### Adding 1 digit number and 2 digit number:

Suppose, a one-digit number is 3 and a two-digit number is 15.

Now,

 T O 3 1 5 1 8

1. First add two ones place digit, 3 + 5 = 8.

2. Then add two tens place digit, 0 + 1 = 1. [if any place value is unavailable, then use o]

3. So, the sum will be 18.

Again,

Suppose, a one-digit number is 5 and a two-digit number is 27.

Now,

 T O 5 2 7 3 2

1. First add two ones place digits, 5 + 7 = 12.

2. The sum of 1st step also has a ten place digit that is 1, so add three ten place digits, 0 + 2 + 1 = 3. [if any place value is unavailable, then use o]

3. 1st step summation’s one place digit and 2nd step summation’s tens place digit make 32.

4. So, the sum is 32.

### Adding two 2 digit numbers:

Suppose, a two digits number is 23 and the other two digits number is 15.

Now,

 T O 2 3 1 5 3 8

1. First add two ones place digit, 3 + 5 = 8.

2. Then add two tens place digit, 2 + 1 = 3.

3. So, the sum will be 38.

Again,

Suppose, a two digits number is 26 and other two digits number is 35.

Now,

 T O 2 6 3 5 6 1

1. First add two ones place digits, 6 + 5 = 11.

2. The sum of 1st step also has a ten-place digit that is 1, so add three ten-place digits, 2 + 3 + 1 = 6.

3. 1st step summation’s one place digit and 2nd step summation’s tens place digit make 61.

4. So, the sum is 61.

(i) 26 + 42

(ii) 53 + 36

(iii) 26 + 37

(iv) 56 + 16

Solution:

(i)

 T O 2 6 4 2 6 8

à Sum of ones place digits: 6 + 2 = 8.

à Sum of tens place digits: 2 + 4 = 6.

à So, the sum is 68.

(ii)

 T O 5 3 3 6 8 9

à Sum of ones place digits: 3 + 6 = 9.

à Sum of tens place digits: 5 + 3 = 8.

à So, the sum is 89.

(iii)

 T O 2 6 3 7 6 3

à Sum of ones place digits: 6 + 7 = 13.

à Sum of tens place digits: 1 + 2 + 3 = 6. [1st tens place digit = 1st summation’s tens place digit]

à So, the sum is 63.

(iv)

 T O 5 6 1 6 7 2

à Sum of ones place digits: 6 + 6 = 12.

à Sum of tens place digits: 1 + 5 + 1 = 7. [1st tens place digit = 1st summation’s tens place digit]

à So, the sum is 72.

(b) Find the sum:

(i) 25 + 12

(ii) 32 + 3

(iii) 44 + 31

(iv) 53 + 24

(vi) 16 + 12

(vii) 36+ 45

(i) 25 + 12 = 37

(ii) 32 + 3 = 35

(iii) 44 + 31 = 75

(iv) 53 + 24 = 77

(vi) 16 + 12 = 28

(vii) 36+ 45 = 81

(c) Find the sum:

(i) 33 + 57

(ii) 32 + 55

(iii) 36 + 26

(iv) 58 + 34

(v) 11 + 33

(vi) 32 + 52

(i) 90

(ii) 87

(iii) 62

(iv) 92

(v) 44

(vi) 84