We are presented with 2312 and 5553. Let's work out the sum.

Step 1: We'll start by adding the digits 2 & 3 in column 1 and get 5.

Step 2: We'll start by adding the digits 1 & 5 in column 2 and get 6.

Step 3: We'll start by adding the digits 3 & 5 in column 3 and get 8.

Step 4: We'll start by adding the digits 2 & 5 in column 4 and get 7.

So, 2312 + 5553 = 7865.

