Let's break this down. We're going to add 8124 and 1612 together.

Step 1: We'll start by adding the digits 4 & 2 in column 1 and get 6.

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

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 7.

Step 4: We'll start by adding the digits 8 & 1 in column 4 and get 9.

So, 8124 + 1612 = 9736.

