OK, let's do this. We've got 3030 and 3849 and we're adding them all together.

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

Step 2: We'll start by adding the digits 3 & 4 in column 2 and get 7.

Step 3: We'll start by adding the digits 0 & 8 in column 3 and get 8.

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

So, 3030 + 3849 = 6879.

