We've got two numbers: 9633 and 7615. Let's find their sum.

Step 1: We'll start by adding the digits 3 & 5 in column 1 and get 8.

Step 2: We'll start by adding the digits 3 & 1 in column 2 and get 4.

Step 3: We'll start by adding the digits 6 & 6 in column 3 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 9 & 7 in column 4 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

So, 9633 + 7615 = 17248.

