Alright, let's solve this problem step by step. We have 1558 and 6011 and we're adding them together.

Step 1: We'll start by adding the digits 8 & 1 in column 1 and get 9.

Step 2: We'll start by adding the digits 5 & 1 in column 2 and get 6.

Step 3: We'll start by adding the digits 5 & 0 in column 3 and get 5.

Step 4: We'll start by adding the digits 1 & 6 in column 4 and get 7.

So, 1558 + 6011 = 7569.

