We've got two numbers: 6817 and 7811. Let's find their sum.

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 1 & 1 in column 2 and get 2.

Step 3: We'll start by adding the digits 8 & 8 in column 3 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 6 & 7 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 6817 + 7811 = 14628.

