Alright, let's solve this problem step by step. We have 2166 and 3613 and we're adding them together.

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

Step 2: We'll start by adding the digits 6 & 1 in column 2 and get 7.

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 7.

Step 4: We'll start by adding the digits 2 & 3 in column 4 and get 5.

So, 2166 + 3613 = 5779.

