Since we have seen the two-digit addition with regrouping,it should not be difficult for you to do the same in three-digit numbers.
Let's see how to add 237 and 116.
Arrange the given three-digit numbers of the math problem as below (one below the other), before adding.
We need to add the numbers in ‘ones’ column, i.e., 7 + 6. Do you get 13? So far, so good.
Now, we cannot write 13 in ‘ones’ column. Write the number 3 in ones column and bring the remaining 1 to the ‘tens’ column.
Write 1 above 3 in the 'tens' column as shown below. This is what we call as regrouping (carrying over) in addition.
The next step in this math problem is to add the two digits in 'tens' column. Adding 3 and 1, we get 4. Now add the carry over 1 along with the 4.
So 4+1=5. Write number 5 in the 'tens' column.
Finally, let us add the numbers in 'hundreds' column as well. 2+1=3. Write 3 in the 'hundreds' column.
We get the answer 353 by adding 237 and 116, which is correct.
Addition of three-digit numbers with regrouping is made easy here.