We are presented with 6819 and 2915. Let's work out the sum.

Step 1: We'll start by adding the digits 9 & 5 in column 1 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

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

Step 3: We'll start by adding the digits 8 & 9 in column 3 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 6 & 2 in column 4 and get 9.

So, 6819 + 2915 = 9734.

