Okay, we are given 819 and 40. Let's add them up step by step.

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

Step 3: We'll start by adding the digits 8 & 0 in column 3 and get 8.

So, 819 + 40 = 859.

