Let's break this down. We're going to add 9651 and 4075 together.

Step 1: We'll start by adding the digits 1 & 5 in column 1 and get 6.

Step 2: We'll start by adding the digits 5 & 7 in column 2 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 6 & 0 in column 3 and get 7.

Step 4: We'll start by adding the digits 9 & 4 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 9651 + 4075 = 13726.

