Okay, we are tasked with adding 4100 and 3125. Let's begin!

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

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

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

Step 4: We'll start by adding the digits 4 & 3 in column 4 and get 7.

So, 4100 + 3125 = 7225.

