Let's break this down. We're going to add 3 and 430 together.

Step 1: We'll start by adding the digits 3 & 0 in column 1 and get 3.

Step 2: We'll start by adding the digits 0 & 3 in column 2 and get 3.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

So, 3 + 430 = 433.

