Let's break this down. We're going to add 152 and 9712 together.

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

Step 2: We'll start by adding the digits 5 & 1 in column 2 and get 6.

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 0 & 9 in column 4 and get 9.

So, 152 + 9712 = 9864.

