Let's break this down. We're going to add 6711 and 1117 together.

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

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

Step 3: We'll start by adding the digits 7 & 1 in column 3 and get 8.

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

So, 6711 + 1117 = 7828.

