OK, let's do this. We've got 4118 and 3661 and we're adding them all together.

Step 1: We'll start by adding the digits 8 & 1 in column 1 and get 9.

Step 2: We'll start by adding the digits 1 & 6 in column 2 and get 7.

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 7.

Step 4: We'll start by adding the digits 4 & 3 in column 4 and get 7.

So, 4118 + 3661 = 7779.

