Let's break this down. We're going to add 6862 and 5311 together.

Step 1: We'll start by adding the digits 2 & 1 in column 1 and get 3.

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 8 & 3 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 6 & 5 in column 4 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 6862 + 5311 = 12173.

