No problem, let's work through this together. We're starting with 9602 and 3873 and adding them all up.

Step 1: We'll start by adding the digits 2 & 3 in column 1 and get 5.

Step 2: We'll start by adding the digits 0 & 7 in column 2 and get 7.

Step 3: We'll start by adding the digits 6 & 8 in column 3 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

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

So, 9602 + 3873 = 13475.

