We are presented with 3367 and 6510. Let's work out the sum.

Step 1: We'll start by adding the digits 7 & 0 in column 1 and get 7.

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 3 & 5 in column 3 and get 8.

Step 4: We'll start by adding the digits 3 & 6 in column 4 and get 9.

So, 3367 + 6510 = 9877.

