Alright, let's solve this problem step by step. We have 5131 and 2723 and we're adding them together.

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

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

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

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

So, 5131 + 2723 = 7854.

