Okay, we are tasked with adding 186 and 6213. Let's begin!

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

Step 2: We'll start by adding the digits 8 & 1 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 0 & 6 in column 4 and get 6.

So, 186 + 6213 = 6399.

