OK, let's do this. We've got 1552 and 5141 and we're adding them all together.

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

Step 2: We'll start by adding the digits 5 & 4 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 1 & 5 in column 4 and get 6.

So, 1552 + 5141 = 6693.

