Alright, let's solve this problem step by step. We have 20 and 794 and we're adding them together.

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

Step 2: We'll start by adding the digits 2 & 9 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 7 in column 3 and get 8.

So, 20 + 794 = 814.

