Okay, we are tasked with adding 4125 and 6681. Let's begin!

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

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

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 8.

Step 4: We'll start by adding the digits 4 & 6 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 4125 + 6681 = 10806.

