Let's get this math done. We have 873 and 5123 and we're going to add them all together.

Step 1: We'll start by adding the digits 3 & 3 in column 1 and get 6.

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

Step 3: We'll start by adding the digits 8 & 1 in column 3 and get 9.

Step 4: We'll start by adding the digits 0 & 5 in column 4 and get 5.

So, 873 + 5123 = 5996.

