We are presented with 3173 and 5412. Let's work out the sum.

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

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

Step 3: We'll start by adding the digits 1 & 4 in column 3 and get 5.

Step 4: We'll start by adding the digits 3 & 5 in column 4 and get 8.

So, 3173 + 5412 = 8585.

