Let's break this down. We're going to add 2401 and 7170 together.

Step 1: We'll start by adding the digits 1 & 0 in column 1 and get 1.

Step 2: We'll start by adding the digits 0 & 7 in column 2 and get 7.

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 5.

Step 4: We'll start by adding the digits 2 & 7 in column 4 and get 9.

So, 2401 + 7170 = 9571.

