81200839 ÷ 809 
Let's see how many times 809 fits into 81200839.

Let's proceed to step 1:
When dividing 8 by 809, we get 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 809

Step 2:
809 goes into 81 0 times with a remainder of 81.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 81, we end up with 81.
Bring next digit (2) of the dividend behind the 81 and repeat the process: 812 / 809

Going ahead to step 3:
809 goes into 812 1 times with a remainder of 3.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
The remainder is 3 after subtracting 809 from 812.
Grab the next digit (0) from the dividend, add it to 3, then carry on: 30 / 809

On to step 4:
30 divided by 809 is 0 with a remainder of 30.
Write down 0 as next digit of the result. 
Result so far: 10.0
If we subtract 0 from 30, we get 30.
Bring next digit (0) of the dividend behind the 30 and repeat the process: 300 / 809

Step 5:
When dividing 300 by 809, we get 0 with a remainder of 300.
Use 0 as the next digit of our solution. 
Result so far: 100.0
If we take 0 away from 300, we end up with 300.
Append the next digit (8) from the dividend to 300 and continue with: 3008 / 809

Advancing to step 6:
If we divide 3008 by 809, we get 3 and a remainder of 581.
Use 3 as the next digit of our solution. 
Result so far: 1003.0
The remainder is 581 after subtracting 2427 from 3008.
Append the next digit (3) from the dividend to 581 and continue with: 5813 / 809

Step 7:
When dividing 5813 by 809, we get 7 with a remainder of 150.
Record the quotient 7 as the next digit in the result. 
Result so far: 10037.0
If we take 5663 away from 5813, we end up with 150.
Include the next digit (9) from the dividend after 150, then repeat: 1509 / 809

Advancing to step 8:
809 goes into 1509 1 times with a remainder of 700.
Use 1 as the next digit of our solution. 
Result so far: 100371.0
Subtract 809 from 1509 to get 700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7000, and continue the process.

Going ahead to step 9:
809 can be fit into 7000 8 times, resulting in a remainder of 528.
Use 8 as the next digit of our solution. 
Result so far: 100371.8
Subtracting 6472 from 7000 leaves us with 528.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5280, and continue the process.

Step 10:
5280 divided by 809 is 6 with a remainder of 426.
Record the quotient 6 as the next digit in the result. 
Result so far: 100371.86
The remainder is 426 after subtracting 4854 from 5280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4260, and continue the process.

Going ahead to step 11:
4260 divided by 809 is 5 with a remainder of 215.
The number 5 becomes the next digit in our result. 
Result so far: 100371.865
Subtract 4045 from 4260 to get 215.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2150, and continue the process.

Advancing to step 12:
2150 divided by 809 is 2 with a remainder of 532.
The number 2 becomes the next digit in our result. 
Result so far: 100371.8652
The remainder is 532 after subtracting 1618 from 2150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5320, and continue the process.

Going ahead to step 13:
When dividing 5320 by 809, we get 6 with a remainder of 466.
Write down 6 as next digit of the result. 
Result so far: 100371.86526
If we subtract 4854 from 5320, we get 466.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4660, and continue the process.

Going ahead to step 14:
The number 809 fits into 4660 5 times, leaving a remainder of 615.
Use 5 as the next digit of our solution. 
Result so far: 100371.865265
If we take 4045 away from 4660, we end up with 615.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6150, and continue the process.

On to step 15:
When dividing 6150 by 809, we get 7 with a remainder of 487.
Record the quotient 7 as the next digit in the result. 
Result so far: 100371.8652657
Deduct 5663 from 6150 and we're left with 487.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4870, and continue the process.

On to step 16:
809 can be fit into 4870 6 times, resulting in a remainder of 16.
The number 6 becomes the next digit in our result. 
Result so far: 100371.86526576
The remainder is 16 after subtracting 4854 from 4870.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final result is 100371.86526576 with a remainder of 1.6e-08.