Add two two-digit numbers – with regrouping

key notes :

2-Digit Addition with Regrouping

2-digit addition with regrouping is a method in which we regroup the given numbers due to a condition. The condition is that if the sum of the numbers in one column is more than 9, we carry forward the extra number to the next column. In the case of 2-digit numbers, regrouping starts from the ones column and we move to the left towards the tens column. Let us understand this with the help of an example.

Example: Add 59 and 23.

Solution: Let us add these numbers using the following steps.

• Step 1: Arrange the numbers or addends according to their place value, i.e., ones and tens column-wise. So, 9 and 3 will be placed under the ones column and 5 and 2 will come under the tens column.
• Step 2: Start adding the numbers from the right, i.e., the ones column and proceed towards the left, i.e., the tens column. Here, 9 + 3 = 12.
• Step 3: If the sum in the ones column is more than 9, we obtain a double-digit number. Taking the double-digit number, we place the ones digit under the ones column and the tens digit is carried forward or regrouped to the next column which is the tens column. Since 12 is greater than 9, we carry forward 1 to the tens column and write 2 as the sum in the ones column.
• Step 4: While adding the tens column, we include the number that was carried forward from the ones column. Hence we add 5 + 2 + 1 (carry-over) = 8.
• Step 5: Once both the columns are added, we obtain the final sum. After adding both the columns, we get 59 + 23 = 82.

Learn with an example

Let’s practice!🖊️