OK, let's do this. We've got 8471 and 1121 and we're adding them all together.

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

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

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

Step 4: We'll start by adding the digits 8 & 1 in column 4 and get 9.

So, 8471 + 1121 = 9592.

