Okay, we are given 8672 and 3893. Let's add them up step by step.

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 7 & 9 in column 2 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 6 & 8 in column 3 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 3 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 8672 + 3893 = 12565.

