Alright, let's solve this problem step by step. We have 634 and 6159 and we're adding them together.

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

Step 2: We'll start by adding the digits 3 & 5 in column 2 and get 9.

Step 3: We'll start by adding the digits 6 & 1 in column 3 and get 7.

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

So, 634 + 6159 = 6793.

