Here we go! We're going to add 252 and 3635 together.

Step 1: We'll start by adding the digits 2 & 5 in column 1 and get 7.

Step 2: We'll start by adding the digits 5 & 3 in column 2 and get 8.

Step 3: We'll start by adding the digits 2 & 6 in column 3 and get 8.

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

So, 252 + 3635 = 3887.

