Okay, we are tasked with adding 8356 and 42. Let's begin!

Step 1: We'll start by adding the digits 6 & 2 in column 1 and get 8.

Step 2: We'll start by adding the digits 5 & 4 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 8 & 0 in column 4 and get 8.

So, 8356 + 42 = 8398.

