OK, let's do this. We've got 6103 and 1125 and we're adding them all together.

Step 1: We'll start by adding the digits 3 & 5 in column 1 and get 8.

Step 2: We'll start by adding the digits 0 & 2 in column 2 and get 2.

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

Step 4: We'll start by adding the digits 6 & 1 in column 4 and get 7.

So, 6103 + 1125 = 7228.

