Okay, we are given 1205 and 8290. Let's add them up step by step.

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

Step 2: We'll start by adding the digits 0 & 9 in column 2 and get 9.

Step 3: We'll start by adding the digits 2 & 2 in column 3 and get 4.

Step 4: We'll start by adding the digits 1 & 8 in column 4 and get 9.

So, 1205 + 8290 = 9495.

