Okay, we are tasked with adding 2642 and 5261. Let's begin!

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

Step 2: We'll start by adding the digits 4 & 6 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 6 & 2 in column 3 and get 9.

Step 4: We'll start by adding the digits 2 & 5 in column 4 and get 7.

So, 2642 + 5261 = 7903.

