Not to worry, we've got 1204 and 3112. Let's get to adding them!

Step 1: We'll start by adding the digits 4 & 2 in column 1 and get 6.

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

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

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

So, 1204 + 3112 = 4316.

