OK, let's do this. We've got 7270 and 3270, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 0 and the borrow 0 from 0 in column 1 and get 0.
0 is the first digit of our result.

Step 2: We'll start by subtracting the digit 7 and the borrow 0 from 7 in column 2 and get 0.
0 is the next digit of our result.

Step 3: We'll start by subtracting the digit 2 and the borrow 0 from 2 in column 3 and get 0.
0 is the next digit of our result.

Step 4: We'll start by subtracting the digit 3 and the borrow 0 from 7 in column 4 and get 4.
4 is the next digit of our result.

So, 7270 - 3270 = 4000.