Okay, let's tackle this math problem. We're starting with 81599 and subtracting 15898.

Step 1: We'll start by subtracting the digit 8 and the borrow 0 from 9 in column 1 and get 1.
1 is the first digit of our result.

Step 2: We'll start by subtracting the digit 9 and the borrow 0 from 9 in column 2 and get 0.
0 is the next digit of our result.

Step 3: We'll start by subtracting the digit 8 and the borrow 0 from 5 in column 3 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 4: We'll start by subtracting the digit 5 and the borrow 1 from 1 in column 4 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

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

So, 81599 - 15898 = 65701.