Okay, we are given 6721 and 3001. Let's add them up step by step.

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

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 7 & 0 in column 3 and get 7.

Step 4: We'll start by adding the digits 6 & 3 in column 4 and get 9.

So, 6721 + 3001 = 9722.

