OK, let's do this. We've got 1101 and 7000 and we're adding them all together.

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

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

Step 3: We'll start by adding the digits 1 & 0 in column 3 and get 1.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1101 + 7000 = 8101.

