What is Addition?
Before we dive into “carry over,” let’s remember what addition means.
Addition is when we combine numbers to find the total.
For example:
If you have 3 apples and your friend gives you 2 apples, together you now have:
3 + 2 = 5 apples.
Addition is like putting things together to make a bigger group.
Why Do We Need Carry Over in Addition?
Most of the time, adding small numbers is easy.
But sometimes, when the numbers are bigger, the total can be more than 9.
That’s when carry over becomes important!
Carry over happens when the sum of digits in one place value (like ones, tens, hundreds) is 10 or more.
Since each place value can only go up to 9, any extra amount has to be moved to the next column.
Think of it like this:
Imagine you have a box that can only hold 9 balls.
If you try to put 12 balls in, the box will overflow!
So you put 2 balls in the box and carry the remaining 1 box of 10 balls to the next shelf.
That’s exactly what happens in addition with carry over!
Place Value and Carry Over
To understand carry over, we need to remember place value:
Ones place – where single units (1-9) are kept.
Tens place – where groups of 10 are kept.
Hundreds place – where groups of 100 are kept.
Thousands place – where groups of 1000 are kept.
For example:
In the number 347,
– 7 is in the ones place
– 4 is in the tens place (means 40)
– 3 is in the hundreds place (means 300)
When we add numbers, we always start from the ones place, then move to the tens, hundreds, and so on.
Carry Over in One-Digit Numbers (No Carry Needed)
Let’s start with a simple example where carry over is not needed.
Example:
4 + 3 = 7
The sum is less than 10, so we write 7 in the ones place.
Easy!
Carry Over in Two-Digit Numbers (Ones to Tens)
Now comes the real part!
Let’s see what happens when the sum is 10 or more.
Example 1:
8
+ 7
—–
Step 1: Add 8 + 7 = 15
Step 2: Write 5 in the ones place.
Step 3: Carry over the 1 (which means 10) to the tens place.
So the answer is 15.
Example 2:
46
+ 27
—–
Step 1: Start with the ones place: 6 + 7 = 13
Write down 3 in the ones place.
Carry over 1 to the tens place.
Step 2: Now add the tens place: 4 + 2 = 6, plus the carried over 1 = 7
So, the answer is 73.
Carry Over in Bigger Numbers (Tens to Hundreds)
Sometimes, carrying over happens more than once!
Example 1:
58
+ 67
—–
Step 1: Ones place → 8 + 7 = 15
Write 5 in the ones place.
Carry over 1 to the tens place.
Step 2: Tens place → 5 + 6 = 11, plus 1 carried = 12
Write 2 in the tens place.
Carry over 1 to the hundreds place.
Final Answer = 125
389
+ 764
——
Step 1: Ones place → 9 + 4 = 13 → Write 3, carry 1
Step 2: Tens place → 8 + 6 = 14, plus 1 = 15 → Write 5, carry 1
Step 3: Hundreds place → 3 + 7 = 10, plus 1 = 11 → Write 11
Answer = 1153
Carry Over in Three-Digit Numbers
Let’s practice with hundreds and thousands.
Example:
356
+ 489
——
Step 1: Ones place → 6 + 9 = 15 → Write 5, carry 1
Step 2: Tens place → 5 + 8 = 13, plus 1 = 14 → Write
