Alright, let's solve this problem step by step. We have 9531 and 156 and we're adding them together.

Step 1: We'll start by adding the digits 1 & 6 in column 1 and get 7.

Step 2: We'll start by adding the digits 3 & 5 in column 2 and get 8.

Step 3: We'll start by adding the digits 5 & 1 in column 3 and get 6.

Step 4: We'll start by adding the digits 9 & 0 in column 4 and get 9.

So, 9531 + 156 = 9687.

