We divide 528604 by 81
The aim is to understand the frequency of 81 in 528604.

Going ahead to step 1:
When dividing 5 by 81, we get 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Grab the next digit (2) from the dividend, add it to 5, then carry on: 52 / 81

Advancing to step 2:
The number 81 fits into 52 0 times, leaving a remainder of 52.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 52 after subtracting 0 from 52.
Append the next digit (8) from the dividend to 52 and continue with: 528 / 81

Let's proceed to step 3:
81 goes into 528 6 times with a remainder of 42.
The number 6 becomes the next digit in our result. 
Result so far: 6.0
If we subtract 486 from 528, we get 42.
Include the next digit (6) from the dividend after 42, then repeat: 426 / 81

Step 4:
81 goes into 426 5 times with a remainder of 21.
Write down 5 as next digit of the result. 
Result so far: 65.0
Deduct 405 from 426 and we're left with 21.
Grab the next digit (0) from the dividend, add it to 21, then carry on: 210 / 81

Let's proceed to step 5:
When dividing 210 by 81, we get 2 with a remainder of 48.
Record the quotient 2 as the next digit in the result. 
Result so far: 652.0
If we take 162 away from 210, we end up with 48.
Include the next digit (4) from the dividend after 48, then repeat: 484 / 81

On to step 6:
If we divide 484 by 81, we get 5 and a remainder of 79.
The next digit of our result is 5. 
Result so far: 6525.0
If we subtract 405 from 484, we get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Going ahead to step 7:
81 can be fit into 790 9 times, resulting in a remainder of 61.
Record the quotient 9 as the next digit in the result. 
Result so far: 6525.9
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.

On to step 8:
81 can be fit into 610 7 times, resulting in a remainder of 43.
Put 7 as the next digit of the answer. 
Result so far: 6525.97
Subtract 567 from 610 to get 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Moving on to step 9:
The number 81 fits into 430 5 times, leaving a remainder of 25.
Use 5 as the next digit of our solution. 
Result so far: 6525.975
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.

Going ahead to step 10:
When dividing 250 by 81, we get 3 with a remainder of 7.
Write down 3 as next digit of the result. 
Result so far: 6525.9753
If we subtract 243 from 250, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Step 11:
81 goes into 70 0 times with a remainder of 70.
Use 0 as the next digit of our solution. 
Result so far: 6525.9753
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.

Advancing to step 12:
The number 81 fits into 700 8 times, leaving a remainder of 52.
Record the quotient 8 as the next digit in the result. 
Result so far: 6525.975308
Subtracting 648 from 700 leaves us 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.

Step 13:
520 divided by 81 is 6 with a remainder of 34.
The number 6 becomes the next digit in our result. 
Result so far: 6525.9753086
If we take 486 away from 520, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Let's proceed to step 14:
The number 81 fits into 340 4 times, leaving a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 6525.97530864
Subtract 324 from 340 to 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.

The final outcome is 6525.97530864, with a leftover of 1.6e-08.