We have numbers 354 and 234. Let's start adding them together.

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

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

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

So, 354 + 234 = 588.

