Addition
- Adding Three Numbers
- Properties of Addition
- Adding Numbers Without Regrouping
- Adding Numbers With Regrouping
Addition is the process of combining two or numbers or things together.
The Sign of addition is + (plus)
Adding Three Numbers
We learnt how to add two numbers by counting.
Consider 5 + 3.
Keep 5 in mind and count 3 more. Five, six, seven, eight.
So, 5 + 3 = 8
Let's find what is 5 + 3 + 2
Let's add 5 and 3 first. We know, 5+ 3 is 8.
Now add 2 to 8.
Keep 8 in mind and count 2 more. eight, nine, ten. 8 + 2 = 10.
So, 5 + 3 + 2 = 10
Here is more examples for you
| Add | Step 1 | Result |
|---|---|---|
| 1 + 2 + 3 | 3 + 3 | 6 |
| 5 + 3 + 1 | 8 + 1 | 11 |
| 3 + 2 + 6 | 5 + 6 | 11 |
| 7 + 3 + 3 | 10 + 3 | 13 |
| 5 + 5 + 3 | 10 + 3 | 13 |
| 4 + 5 + 1 | 9 + 1 | 10 |
| 8 + 5 + 1 | 13 + 1 | 14 |
Properties of Addition
| Property | Definition | Example |
|---|---|---|
| Adding 0 | When we add 0 to a number, the sum is the number itself. | 5 + 0 = 5 4 + 0 = 4 |
| Adding 1 | When we add 1 to a number, the sum is the next immediate number. | 5 + 1 = 6 8 + 1 = 9 |
| Order of Addition | Numbers can be added in any order. Their sum remains the same | 5 + 2 = 7 2 + 5 = 7 |
Adding Numbers Without Regrouping
Let's find 20 + 15 + 12Step 1:
Write the numbers like below.1 5
+ 1 2
Step 2:
Add the ONES and write the sum in the ones place.1 5
+ 1 2
7
Step 3:
Add the TENS and write the sum in the tens place.1 5
+ 1 2
47
Adding Numbers With Regrouping
In the previous section of addition, when we add the ones, the sum was always a 1-digit number or sum was always less than 10.
This was the same for the digts in tens place as well.
Let's try to add a differenr set of numbers
Step 1:
Write the numbers like below.+ 2 6
Step 2:
Add the ONES. 7 + 6 = 13. Regroup 13 ones.13 Ones = 1 Tens + 3 Ones
Write 3 in ones place, carry over 1 ten to the tens place.
1 7
+ 2 6
3
Step 3:
Add the TENS, 1 + 1 + 2 = 4. Write 4 in tens place.1 7
+ 2 6
4 3