OK, let's do this. We've got 4107 and 5781 and we're adding them all together.

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

Step 2: We'll start by adding the digits 0 & 8 in column 2 and get 8.

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

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

So, 4107 + 5781 = 9888.

