We are presented with 2312 and 7175. Let's work out the sum.

Step 1: We'll start by adding the digits 2 & 5 in column 1 and get 7.

Step 2: We'll start by adding the digits 1 & 7 in column 2 and get 8.

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

Step 4: We'll start by adding the digits 2 & 7 in column 4 and get 9.

So, 2312 + 7175 = 9487.

