We look at the division of 559159 by 81 
The aim is to understand the frequency of 81 in 559159.

Advancing to step 1:
If we divide 5 by 81, we get 0 and a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Grab the next digit (5) from the dividend, add it to 5, then carry on: 55 / 81

Moving on to step 2:
55 divided by 81 is 0 with a remainder of 55.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 55 to get 55.
Take the next digit (9) from the dividend and append it to 55, then repeat: 559 / 81

On to step 3:
559 divided by 81 is 6 with a remainder of 73.
Record the quotient 6 as the next digit in the result. 
Result so far: 6.0
The remainder is 73 after subtracting 486 from 559.
Include the next digit (1) from the dividend after 73, then repeat: 731 / 81

Step 4:
81 can be fit into 731 9 times, resulting in a remainder of 2.
The next digit of our result is 9. 
Result so far: 69.0
Subtract 729 from 731 to get 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 81

Let's proceed to step 5:
25 divided by 81 is 0 with a remainder of 25.
Record the quotient 0 as the next digit in the result. 
Result so far: 690.0
Subtracting 0 from 25 leaves us with 25.
Append the next digit (9) from the dividend to 25 and continue with: 259 / 81

Let's proceed to step 6:
When dividing 259 by 81, we get 3 with a remainder of 16.
Write down 3 as next digit of the result. 
Result so far: 6903.0
If we subtract 243 from 259, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 7:
160 divided by 81 is 1 with a remainder of 79.
The next digit of our result is 1. 
Result so far: 6903.1
If we take 81 away from 160, we end up with 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Step 8:
81 goes into 790 9 times with a remainder of 61.
Record the quotient 9 as the next digit in the result. 
Result so far: 6903.19
If we subtract 729 from 790, we get 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

Going ahead to step 9:
81 goes into 610 7 times with a remainder of 43.
Use 7 as the next digit of our solution. 
Result so far: 6903.197
If we take 567 away from 610, we end up with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Advancing to step 10:
430 divided by 81 is 5 with a remainder of 25.
Put 5 as the next digit of the answer. 
Result so far: 6903.1975
If we subtract 405 from 430, we get 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Moving on to step 11:
250 divided by 81 is 3 with a remainder of 7.
Use 3 as the next digit of our solution. 
Result so far: 6903.19753
The remainder is 7 after subtracting 243 from 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Let's proceed to step 12:
When dividing 70 by 81, we get 0 with a remainder of 70.
The number 0 becomes the next digit in our result. 
Result so far: 6903.19753
If we take 0 away from 70, we end up with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

On to step 13:
700 divided by 81 is 8 with a remainder of 52.
Record the quotient 8 as the next digit in the result. 
Result so far: 6903.1975308
If we take 648 away from 700, we end up with 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

On to step 14:
81 can be fit into 520 6 times, resulting in a remainder of 34.
Record the quotient 6 as the next digit in the result. 
Result so far: 6903.19753086
If we subtract 486 from 520, we get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

After the division, we end up with 6903.19753086 and a remainder of 3.4e-08.