Not to worry, we've got 233 and 154. Let's get to adding them!

Step 1: We'll start by adding the digits 3 & 4 in column 1 and get 7.

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

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

So, 233 + 154 = 387.

