Let's break this down. We're going to add 6091 and 2444 together.

Step 1: We'll start by adding the digits 1 & 4 in column 1 and get 5.

Step 2: We'll start by adding the digits 9 & 4 in column 2 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 5.

Step 4: We'll start by adding the digits 6 & 2 in column 4 and get 8.

So, 6091 + 2444 = 8535.

