OK, let's do this. We've got 81839 and 61914, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 9 in column 1 and get 5.
5 is the first digit of our result.

Step 2: We'll start by subtracting the digit 1 and the borrow 0 from 3 in column 2 and get 2.
2 is the next digit of our result.

Step 3: We'll start by subtracting the digit 9 and the borrow 0 from 8 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 1 and the borrow 1 from 1 in column 4 and get -1.
We add -1 to 10 and get 9 as the next digit of the result.

Step 5: We'll start by subtracting the digit 6 and the borrow 1 from 8 in column 5 and get 1.
1 is the next digit of our result.

So, 81839 - 61914 = 19925.