Alright, let's solve this problem step by step. We have 2520 and 5255 and we're adding them together.

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 2 & 5 in column 2 and get 7.

Step 3: We'll start by adding the digits 5 & 2 in column 3 and get 7.

Step 4: We'll start by adding the digits 2 & 5 in column 4 and get 7.

So, 2520 + 5255 = 7775.

