Let's break this down. We're going to add 3860 and 9204 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 6 & 0 in column 2 and get 6.

Step 3: We'll start by adding the digits 8 & 2 in column 3 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

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

So, 3860 + 9204 = 13064.

