We're dividing 518901 by 81 
The aim is to understand the frequency of 81 in 518901.

Going ahead to step 1:
The number 81 fits into 5 0 times, leaving a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Include the next digit (1) from the dividend after 5, then repeat: 51 / 81

Moving on to step 2:
The number 81 fits into 51 0 times, leaving a remainder of 51.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 51, we get 51.
Include the next digit (8) from the dividend after 51, then repeat: 518 / 81

On to step 3:
81 can be fit into 518 6 times, resulting in a remainder of 32.
Write down 6 as next digit of the result. 
Result so far: 6.0
Deduct 486 from 518 and we're left with 32.
Append the next digit (9) from the dividend to 32 and continue with: 329 / 81

Moving on to step 4:
If we divide 329 by 81, we get 4 and a remainder of 5.
Use 4 as the next digit of our solution. 
Result so far: 64.0
The remainder is 5 after subtracting 324 from 329.
Append the next digit (0) from the dividend to 5 and continue with: 50 / 81

Advancing to step 5:
The number 81 fits into 50 0 times, leaving a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 640.0
Subtracting 0 from 50 leaves us with 50.
Bring next digit (1) of the dividend behind the 50 and repeat the process: 501 / 81

Advancing to step 6:
81 can be fit into 501 6 times, resulting in a remainder of 15.
The next digit of our result is 6. 
Result so far: 6406.0
The remainder is 15 after subtracting 486 from 501.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 7:
81 goes into 150 1 times with a remainder of 69.
Record the quotient 1 as the next digit in the result. 
Result so far: 6406.1
If we take 81 away from 150, 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.

Going ahead to step 8:
If we divide 690 by 81, we get 8 and a remainder of 42.
Use 8 as the next digit of our solution. 
Result so far: 6406.18
Subtracting 648 from 690 leaves us 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.

Step 9:
81 can be fit into 420 5 times, resulting in a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 6406.185
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.

On to step 10:
81 goes into 150 1 times with a remainder of 69.
Record the quotient 1 as the next digit in the result. 
Result so far: 6406.1851
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.

Advancing to step 11:
690 divided by 81 is 8 with a remainder of 42.
The next digit of our result is 8. 
Result so far: 6406.18518
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.

On to step 12:
81 goes into 420 5 times with a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 6406.185185
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.

Advancing to step 13:
81 goes into 150 1 times with a remainder of 69.
Record the quotient 1 as the next digit in the result. 
Result so far: 6406.1851851
Deduct 81 from 150 and we're left 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.

Advancing to step 14:
The number 81 fits into 690 8 times, leaving a remainder of 42.
Record the quotient 8 as the next digit in the result. 
Result so far: 6406.18518518
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.

The quotient of the division is 6406.18518518, and the remainder is 4.2e-08.