Alright, let's solve this problem step by step. We have 735 and 108 and we're adding them together.

Step 1: We'll start by adding the digits 5 & 8 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 & 0 in column 2 and get 4.

Step 3: We'll start by adding the digits 7 & 1 in column 3 and get 8.

So, 735 + 108 = 843.

