We look at the division of 825809 by 81 
The aim is to understand the frequency of 81 in 825809.

Let's proceed to step 1:
When dividing 8 by 81, we get 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Fetch the next digit (2) from the dividend, attach it to 8 and continue: 82 / 81

Step 2:
The number 81 fits into 82 1 times, leaving a remainder of 1.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we take 81 away from 82, we end up with 1.
Grab the next digit (5) from the dividend, add it to 1, then carry on: 15 / 81

Advancing to step 3:
If we divide 15 by 81, we get 0 and a remainder of 15.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
The remainder is 15 after subtracting 0 from 15.
Take the next digit (8) from the dividend and append it to 15, then repeat: 158 / 81

On to step 4:
If we divide 158 by 81, we get 1 and a remainder of 77.
Record the quotient 1 as the next digit in the result. 
Result so far: 101.0
The remainder is 77 after subtracting 81 from 158.
Fetch the next digit (0) from the dividend, attach it to 77 and continue: 770 / 81

Advancing to step 5:
81 can be fit into 770 9 times, resulting in a remainder of 41.
Write down 9 as next digit of the result. 
Result so far: 1019.0
Subtracting 729 from 770 leaves us with 41.
Take the next digit (9) from the dividend and append it to 41, then repeat: 419 / 81

Let's proceed to step 6:
The number 81 fits into 419 5 times, leaving a remainder of 14.
Write down 5 as next digit of the result. 
Result so far: 10195.0
The remainder is 14 after subtracting 405 from 419.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 7:
If we divide 140 by 81, we get 1 and a remainder of 59.
Put 1 as the next digit of the answer. 
Result so far: 10195.1
The remainder is 59 after subtracting 81 from 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 590, and continue the process.

Step 8:
When dividing 590 by 81, we get 7 with a remainder of 23.
Put 7 as the next digit of the answer. 
Result so far: 10195.17
The remainder is 23 after subtracting 567 from 590.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Advancing to step 9:
The number 81 fits into 230 2 times, leaving a remainder of 68.
The number 2 becomes the next digit in our result. 
Result so far: 10195.172
Subtracting 162 from 230 leaves us with 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Advancing to step 10:
81 goes into 680 8 times with a remainder of 32.
Write down 8 as next digit of the result. 
Result so far: 10195.1728
If we subtract 648 from 680, we get 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Going ahead to step 11:
81 goes into 320 3 times with a remainder of 77.
Write down 3 as next digit of the result. 
Result so far: 10195.17283
Subtracting 243 from 320 leaves us with 77.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

Advancing to step 12:
When dividing 770 by 81, we get 9 with a remainder of 41.
Use 9 as the next digit of our solution. 
Result so far: 10195.172839
Deduct 729 from 770 and we're left with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Going ahead to step 13:
81 goes into 410 5 times with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 10195.1728395
If we subtract 405 from 410, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 14:
81 goes into 50 0 times with a remainder of 50.
The next digit of our result is 0. 
Result so far: 10195.1728395
If we subtract 0 from 50, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

In conclusion, the division gives 10195.1728395 with a balance of 5e-08.