We look at the division of 839958 by 81 
The aim is to understand the frequency of 81 in 839958.

Moving on to step 1:
When dividing 8 by 81, we get 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Take the next digit (3) from the dividend and append it to 8, then repeat: 83 / 81

Advancing to step 2:
When dividing 83 by 81, we get 1 with a remainder of 2.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we take 81 away from 83, we end up with 2.
Take the next digit (9) from the dividend and append it to 2, then repeat: 29 / 81

Step 3:
The number 81 fits into 29 0 times, leaving a remainder of 29.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Subtract 0 from 29 to get 29.
Include the next digit (9) from the dividend after 29, then repeat: 299 / 81

Step 4:
The number 81 fits into 299 3 times, leaving a remainder of 56.
The number 3 becomes the next digit in our result. 
Result so far: 103.0
The remainder is 56 after subtracting 243 from 299.
Take the next digit (5) from the dividend and append it to 56, then repeat: 565 / 81

Step 5:
When dividing 565 by 81, we get 6 with a remainder of 79.
The number 6 becomes the next digit in our result. 
Result so far: 1036.0
Subtract 486 from 565 to get 79.
Grab the next digit (8) from the dividend, add it to 79, then carry on: 798 / 81

Step 6:
If we divide 798 by 81, we get 9 and a remainder of 69.
Put 9 as the next digit of the answer. 
Result so far: 10369.0
If we take 729 away from 798, we end up with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Moving on to step 7:
690 divided by 81 is 8 with a remainder of 42.
The number 8 becomes the next digit in our result. 
Result so far: 10369.8
The remainder is 42 after subtracting 648 from 690.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Let's proceed to step 8:
81 can be fit into 420 5 times, resulting in a remainder of 15.
The next digit of our result is 5. 
Result so far: 10369.85
If we take 405 away from 420, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 9:
The number 81 fits into 150 1 times, leaving a remainder of 69.
Write down 1 as next digit of the result. 
Result so far: 10369.851
Subtracting 81 from 150 leaves us with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Moving on to step 10:
690 divided by 81 is 8 with a remainder of 42.
The next digit of our result is 8. 
Result so far: 10369.8518
Deduct 648 from 690 and we're left with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Advancing to step 11:
81 goes into 420 5 times with a remainder of 15.
The next digit of our result is 5. 
Result so far: 10369.85185
Deduct 405 from 420 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 12:
If we divide 150 by 81, we get 1 and a remainder of 69.
Put 1 as the next digit of the answer. 
Result so far: 10369.851851
If we subtract 81 from 150, we get 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

On to step 13:
If we divide 690 by 81, we get 8 and a remainder of 42.
The number 8 becomes the next digit in our result. 
Result so far: 10369.8518518
If we take 648 away from 690, we end up with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Moving on to step 14:
If we divide 420 by 81, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 10369.85185185
If we subtract 405 from 420, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The quotient of the division is 10369.85185185, and the remainder is 1.5e-08.