OK, let's do this. We've got 428 and 6018 and we're adding them all together.

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

Step 2: We'll start by adding the digits 2 & 1 in column 2 and get 4.

Step 3: We'll start by adding the digits 4 & 0 in column 3 and get 4.

Step 4: We'll start by adding the digits 0 & 6 in column 4 and get 6.

So, 428 + 6018 = 6446.

