We look at the division of 904279 by 81 
The aim is to understand the frequency of 81 in 904279.

On to step 1:
81 goes into 9 0 times with a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 9 to get 9.
Append the next digit (0) from the dividend to 9 and continue with: 90 / 81

Moving on to step 2:
90 divided by 81 is 1 with a remainder of 9.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 81 from 90 and we're left with 9.
Take the next digit (4) from the dividend and append it to 9, then repeat: 94 / 81

Moving on to step 3:
If we divide 94 by 81, we get 1 and a remainder of 13.
Record the quotient 1 as the next digit in the result. 
Result so far: 11.0
If we subtract 81 from 94, we get 13.
Grab the next digit (2) from the dividend, add it to 13, then carry on: 132 / 81

Going ahead to step 4:
When dividing 132 by 81, we get 1 with a remainder of 51.
The next digit of our result is 1. 
Result so far: 111.0
Subtract 81 from 132 to get 51.
Append the next digit (7) from the dividend to 51 and continue with: 517 / 81

On to step 5:
81 goes into 517 6 times with a remainder of 31.
Write down 6 as next digit of the result. 
Result so far: 1116.0
Deduct 486 from 517 and we're left with 31.
Include the next digit (9) from the dividend after 31, then repeat: 319 / 81

Moving on to step 6:
319 divided by 81 is 3 with a remainder of 76.
Put 3 as the next digit of the answer. 
Result so far: 11163.0
Subtract 243 from 319 to get 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

On to step 7:
When dividing 760 by 81, we get 9 with a remainder of 31.
Put 9 as the next digit of the answer. 
Result so far: 11163.9
Subtract 729 from 760 to get 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Moving on to step 8:
81 goes into 310 3 times with a remainder of 67.
Put 3 as the next digit of the answer. 
Result so far: 11163.93
Subtracting 243 from 310 leaves us with 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

On to step 9:
81 can be fit into 670 8 times, resulting in a remainder of 22.
The next digit of our result is 8. 
Result so far: 11163.938
If we take 648 away from 670, we end up with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Let's proceed to step 10:
220 divided by 81 is 2 with a remainder of 58.
The next digit of our result is 2. 
Result so far: 11163.9382
If we subtract 162 from 220, we get 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Let's proceed to step 11:
81 goes into 580 7 times with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 11163.93827
Subtract 567 from 580 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 12:
When dividing 130 by 81, we get 1 with a remainder of 49.
Put 1 as the next digit of the answer. 
Result so far: 11163.938271
If we take 81 away from 130, we end up with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Going ahead to step 13:
The number 81 fits into 490 6 times, leaving a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 11163.9382716
Subtracting 486 from 490 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 14:
The number 81 fits into 40 0 times, leaving a remainder of 40.
Write down 0 as next digit of the result. 
Result so far: 11163.9382716
Deduct 0 from 40 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Our division results in 11163.9382716 with a remaining 4e-08.