Okay, we are tasked with adding 1025 and 5401. 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 & 0 in column 2 and get 2.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

Step 4: We'll start by adding the digits 1 & 5 in column 4 and get 6.

So, 1025 + 5401 = 6426.

