Alright, let's solve this problem step by step. We have 8905 and 9802 and we're adding them together.

Step 1: We'll start by adding the digits 5 & 2 in column 1 and get 7.

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

Step 3: We'll start by adding the digits 9 & 8 in column 3 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 9 in column 4 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

So, 8905 + 9802 = 18707.

