Okay, we are tasked with adding 3319 and 6580. Let's begin!

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

Step 2: We'll start by adding the digits 1 & 8 in column 2 and get 9.

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, 3319 + 6580 = 9899.

