864399 ÷ 81 
We want to divide 864399 by 81.

Moving on to step 1:
The number 81 fits into 8 0 times, leaving a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Take the next digit (6) from the dividend and append it to 8, then repeat: 86 / 81

On to step 2:
The number 81 fits into 86 1 times, leaving a remainder of 5.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 81 from 86 and we're left with 5.
Include the next digit (4) from the dividend after 5, then repeat: 54 / 81

Step 3:
The number 81 fits into 54 0 times, leaving a remainder of 54.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Deduct 0 from 54 and we're left with 54.
Grab the next digit (3) from the dividend, add it to 54, then carry on: 543 / 81

Step 4:
81 can be fit into 543 6 times, resulting in a remainder of 57.
Record the quotient 6 as the next digit in the result. 
Result so far: 106.0
Subtracting 486 from 543 leaves us with 57.
Take the next digit (9) from the dividend and append it to 57, then repeat: 579 / 81

Moving on to step 5:
81 can be fit into 579 7 times, resulting in a remainder of 12.
Use 7 as the next digit of our solution. 
Result so far: 1067.0
The remainder is 12 after subtracting 567 from 579.
Grab the next digit (9) from the dividend, add it to 12, then carry on: 129 / 81

Moving on to step 6:
129 divided by 81 is 1 with a remainder of 48.
The next digit of our result is 1. 
Result so far: 10671.0
Subtract 81 from 129 to get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Let's proceed to step 7:
The number 81 fits into 480 5 times, leaving a remainder of 75.
The number 5 becomes the next digit in our result. 
Result so far: 10671.5
Subtracting 405 from 480 leaves us with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

On to step 8:
The number 81 fits into 750 9 times, leaving a remainder of 21.
Put 9 as the next digit of the answer. 
Result so far: 10671.59
Subtract 729 from 750 to get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Going ahead to step 9:
81 can be fit into 210 2 times, resulting in a remainder of 48.
Record the quotient 2 as the next digit in the result. 
Result so far: 10671.592
Subtracting 162 from 210 leaves us with 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Step 10:
81 goes into 480 5 times with a remainder of 75.
Record the quotient 5 as the next digit in the result. 
Result so far: 10671.5925
The remainder is 75 after subtracting 405 from 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Advancing to step 11:
81 can be fit into 750 9 times, resulting in a remainder of 21.
The next digit of our result is 9. 
Result so far: 10671.59259
The remainder is 21 after subtracting 729 from 750.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Moving on to step 12:
210 divided by 81 is 2 with a remainder of 48.
The number 2 becomes the next digit in our result. 
Result so far: 10671.592592
The remainder is 48 after subtracting 162 from 210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Going ahead to step 13:
The number 81 fits into 480 5 times, leaving a remainder of 75.
The next digit of our result is 5. 
Result so far: 10671.5925925
Deduct 405 from 480 and we're left with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Step 14:
750 divided by 81 is 9 with a remainder of 21.
Record the quotient 9 as the next digit in the result. 
Result so far: 10671.59259259
If we take 729 away from 750, we end up with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Our division results in 10671.59259259 with a remaining 2.1e-08.