We have numbers 3107 and 6312. Let's start adding them together.

Step 1: We'll start by adding the digits 7 & 2 in column 1 and get 9.

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 1 & 3 in column 3 and get 4.

Step 4: We'll start by adding the digits 3 & 6 in column 4 and get 9.

So, 3107 + 6312 = 9419.

