OK, let's do this. We've got 1145 and 7013 and we're adding them all together.

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

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

Step 3: We'll start by adding the digits 1 & 0 in column 3 and get 1.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1145 + 7013 = 8158.

