Let's break this down. We're going to add 1101 and 2700 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 & 7 in column 3 and get 8.

Step 4: We'll start by adding the digits 1 & 2 in column 4 and get 3.

So, 1101 + 2700 = 3801.

