OK, let's do this. We've got 1557 and 6130 and we're adding them all together.

Step 1: We'll start by adding the digits 7 & 0 in column 1 and get 7.

Step 2: We'll start by adding the digits 5 & 3 in column 2 and get 8.

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 & 6 in column 4 and get 7.

So, 1557 + 6130 = 7687.

