Alright, let's solve this problem step by step. We have 407 and 111 and we're adding them together.

Step 1: We'll start by adding the digits 7 & 1 in column 1 and get 8.

Step 2: We'll start by adding the digits 0 & 1 in column 2 and get 1.

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

So, 407 + 111 = 518.

