OK, let's do this. We've got 2512 and 5176 and we're adding them all together.

Step 1: We'll start by adding the digits 2 & 6 in column 1 and get 8.

Step 2: We'll start by adding the digits 1 & 7 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 2 & 5 in column 4 and get 7.

So, 2512 + 5176 = 7688.

