Okay, we are tasked with adding 2521 and 4425. Let's begin!

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

Step 2: We'll start by adding the digits 2 & 2 in column 2 and get 4.

Step 3: We'll start by adding the digits 5 & 4 in column 3 and get 9.

Step 4: We'll start by adding the digits 2 & 4 in column 4 and get 6.

So, 2521 + 4425 = 6946.

