Got it! So, we have 72194 and 64217, and we'll subtract the latter from the former.

Step 1: We'll start by subtracting the digit 7 and the borrow 0 from 4 in column 1 and get -3.
We add -3 to 10 and get 7 as the first digit of the result.

Step 2: We'll start by subtracting the digit 1 and the borrow 1 from 9 in column 2 and get 7.
7 is the next digit of our result.

Step 3: We'll start by subtracting the digit 2 and the borrow 0 from 1 in column 3 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 4: We'll start by subtracting the digit 4 and the borrow 1 from 2 in column 4 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 5: We'll start by subtracting the digit 6 and the borrow 1 from 7 in column 5 and get 0.
0 is the next digit of our result.

So, 72194 - 64217 = 7977.