Alright, let's solve this problem step by step. We have 3111 and 7101 and we're adding them together.

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

Step 2: We'll start by adding the digits 1 & 0 in column 2 and get 1.

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

Step 4: We'll start by adding the digits 3 & 7 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 3111 + 7101 = 10212.

