Okay, we are given 2391 and 328. Let's add them up step by step.

Step 1: We'll start by adding the digits 1 & 8 in column 1 and get 9.

Step 2: We'll start by adding the digits 9 & 2 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

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

Step 4: We'll start by adding the digits 2 & 0 in column 4 and get 2.

So, 2391 + 328 = 2719.

