Okay, we are tasked with adding 1620 and 6201. Let's begin!

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

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

Step 3: We'll start by adding the digits 6 & 2 in column 3 and get 8.

Step 4: We'll start by adding the digits 1 & 6 in column 4 and get 7.

So, 1620 + 6201 = 7821.

