OK, let's do this. We've got 427 and 8522 and we're adding them all together.

Step 1: We'll start by adding the digits 7 & 2 in column 1 and get 9.

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

Step 3: We'll start by adding the digits 4 & 5 in column 3 and get 9.

Step 4: We'll start by adding the digits 0 & 8 in column 4 and get 8.

So, 427 + 8522 = 8949.

