OK, let's do this. We've got 111 and 8542 and we're adding them all together.

Step 1: We'll start by adding the digits 1 & 2 in column 1 and get 3.

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

Step 3: We'll start by adding the digits 1 & 5 in column 3 and get 6.

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

So, 111 + 8542 = 8653.

