Okay, we are given 3111 and 104. Let's add them up step by step.

Step 1: We'll start by adding the digits 1 & 4 in column 1 and get 5.

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 & 0 in column 4 and get 3.

So, 3111 + 104 = 3215.

