Alright, let's solve this problem step by step. We have 3624 and 5253 and we're adding them together.

Step 1: We'll start by adding the digits 4 & 3 in column 1 and get 7.

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 6 & 2 in column 3 and get 8.

Step 4: We'll start by adding the digits 3 & 5 in column 4 and get 8.

So, 3624 + 5253 = 8877.

