OK, let's do this. We've got 233 and 3217 and we're adding them all together.

Step 1: We'll start by adding the digits 3 & 7 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 3 & 1 in column 2 and get 5.

Step 3: We'll start by adding the digits 2 & 2 in column 3 and get 4.

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

So, 233 + 3217 = 3450.

