The operation to find the total of different values is called addition. Let us know some facts about addition which will help us to learn to add 4-digit and 5-digit numbers.

1. Addition of small numbers can be done horizontally.

Example: 6 + 2 + 3 = 11

2. Large numbers are added in vertical columns (written under the place value chart).

Example:

Th     H     T     O

7     2     5     8

1     3     6     2

+       1     4     2     6

1       0     0     4     6

3. A zero added to a number does not change the place value of the number.

H     T     O

3     2     5

+                   0

3     2     5

4. The number or values being added are called addends and the answer is called the sum.

5. 1 added to a number gives the successor of the number as the sum.

6. To find a missing addend in an addition sum, the given addend or the sum of all the given addends is subtracted from the given sum.

Workings:

7. Changing the order of the addend in an addition sum does not change the answer.

Example: (i) 45 + 26 = 26 + 45 = 71

(ii) 3 + 2 + 6 = 6 + 2 + 3 = 11

8. While adding more than two numbers, we can group any two numbers first. It does not change the sum.

Example: 7 + (9 + 3) = 7 + 12 = 19

or

(7 + 3) + 9 = 10 + 9 = 19

This fact helps us to group any two addends to make addition easy.

Example: = (95 + 5) + 23

= 100 + 23

= 123

3rd Grade Math Lessons