Addition Class 2 Notes Maths

Addition of Three 2-Digit Numbers

Example: Add 36, 24, and 25.

We add three numbers in the same way as we add two numbers.
Step 1. Arrange the numbers in the columns of tens and ones.
Step 2. Add the ones.

6 ones + 4 ones + 5 ones = 15 ones
= 1 ten + 5 ones
Write 5 in the ones column and carry over 1 ten to the tens column.

Step 3. Add the tens.
1 ten (carried over) + 3 tens + 2 tens + 2 tens = 8 tens
Write 8 in the tens column.
So, 36 + 24 + 25 = 85.

Addition of Larger 2-Digit Numbers 

Example: Find the sum of 85 and 49.

Step 1. Arrange the numbers in the columns of tens and ones.
Step 2. Add the ones.
5 ones + 9 ones = 14 ones = 1 ten + 4 ones
Write 4 in the ones column and carry over 1 ten to the tens column.
Step 3. Add the tens.
1 ten (carried over) + 8 tens + 4 tens = 13 tens = 1 hundred 3 tens
Write 3 in the tens column and 1 in the hundreds column.
So, 85 + 49 = 134.

Example: There are 28 books on one shelf and 24 books on the other shelf. How many books are there on both shelves?

Number of books in one shelf = 28

Number of books in the other shelf = 24

Therefore, number of books in both the shelves= 28 + 24 = 52.

Adding 3-Digit Numbers (Without Carrying)

Method 1: Using the Expanded Form

So, 234 + 215 = 449.

Method 2: Using the Short Form

Adding 3-Digit Numbers (With Carrying)

Carrying from Ones to Tens

Example: Let us add 357 and 328.

Method 1: Using the Expanded Form

Method 2: Using the Short Form

Write the numbers in column form as shown

Example: Add 348 and 125.

Step 1. Add the ones.

8 ones + 5 ones = 13 ones = 1 ten + 3 ones

Write 3 under the ones column and carry 1 ten to the tens column.

Step 2. Add the tens.

1 ten (carried over) + 4 tens + 2 tens = 7 tens

Write 7 under the tens column.

Step 3. Add the hundreds.

3 hundreds + 1 hundred = 4 hundreds

Write 4 under the hundreds column.

So, 348 + 125 = 473.

Carrying from Ones to Tens and from Tens to Hundreds

Let us add 394 and 528

Method 1: Using the Expanded Form

Method 2: Using the Short Form

Example: Add 693 and 278.

Step 1. Add the ones.

3 ones + 8 ones = 11 ones = 1 ten + 1 one

Write 1 under the ones column and carry 1 ten to tens column.

Step 2. Add the tens.

1 ten (carried over) + 9 tens + 7 tens = 17 tens = 1 hundred + 7 tens

Write 7 under the tens column and carry 1 hundred to the hundreds column.

Step 3. Add the hundreds.

1 hundred (carried over) + 6 hundreds + 2 hundreds = 9 hundreds

Write 9 under the hundreds column.

So, 693 + 278 = 971.