Alright, let's solve this problem step by step. We have 2500 and 6161 and we're adding them together.

Step 1: We'll start by adding the digits 0 & 1 in column 1 and get 1.

Step 2: We'll start by adding the digits 0 & 6 in column 2 and get 6.

Step 3: We'll start by adding the digits 5 & 1 in column 3 and get 6.

Step 4: We'll start by adding the digits 2 & 6 in column 4 and get 8.

So, 2500 + 6161 = 8661.

