Page 67 - Math Skill - 2

Addition and Subtraction of 3-digit Numbers 65

Addition with Regrouping

3-digit number with a 2-digit number

Let us add 837 and 78.

H T O
Step 1: Write the numbers in columns.
1

Step 2: Add the ones. 7 + 8 = 15 ones 8 3 7

15 ones = 1 ten + 5 ones + 7 8

Write 5 in ones column and carry over 1 ten 5

to the tens column.

H T O
Step 3: Add the tens. 3 + 7 + 1 (carried over) = 11 tens 1 1

11 tens = 10 tens + 1 ten = 1 hundred + 1 ten 8 3 7

Write 1 in tens column and carry over + 7 8

1 hundred to the hundreds column. 1 5

Step 4: Add the hundreds. H T O
1
1
8 + 0 + 1 (carried over) = 9 hundreds 8 3 7

Write 9 in hundreds column. + 0 7 8

Thus, 837 + 78 = 915 9 1 5

3-digit number with a 3-digit number

H T O
Let us add 591 and 274.

Step 1: Add the ones. 1 + 4 = 5 ones. 5 9 1

Write 5 in ones column. + 2 7 4
5