Okay, we are tasked with adding 255 and 6641. Let's begin!

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

Step 2: We'll start by adding the digits 5 & 4 in column 2 and get 9.

Step 3: We'll start by adding the digits 2 & 6 in column 3 and get 8.

Step 4: We'll start by adding the digits 0 & 6 in column 4 and get 6.

So, 255 + 6641 = 6896.

