Okay, we are tasked with adding 6720 and 3330. Let's begin!

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

Step 2: We'll start by adding the digits 2 & 3 in column 2 and get 5.

Step 3: We'll start by adding the digits 7 & 3 in column 3 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 6 & 3 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 6720 + 3330 = 10050.

