We're dividing 609613 by 81 
The aim is to understand the frequency of 81 in 609613.

On to step 1:
81 can be fit into 6 0 times, resulting in a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Grab the next digit (0) from the dividend, add it to 6, then carry on: 60 / 81

Let's proceed to step 2:
60 divided by 81 is 0 with a remainder of 60.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 60 after subtracting 0 from 60.
Include the next digit (9) from the dividend after 60, then repeat: 609 / 81

Moving on to step 3:
When dividing 609 by 81, we get 7 with a remainder of 42.
Write down 7 as next digit of the result. 
Result so far: 7.0
Deduct 567 from 609 and we're left with 42.
Include the next digit (6) from the dividend after 42, then repeat: 426 / 81

Let's proceed to step 4:
426 divided by 81 is 5 with a remainder of 21.
Record the quotient 5 as the next digit in the result. 
Result so far: 75.0
If we take 405 away from 426, we end up with 21.
Bring next digit (1) of the dividend behind the 21 and repeat the process: 211 / 81

Going ahead to step 5:
When dividing 211 by 81, we get 2 with a remainder of 49.
Record the quotient 2 as the next digit in the result. 
Result so far: 752.0
The remainder is 49 after subtracting 162 from 211.
Fetch the next digit (3) from the dividend, attach it to 49 and continue: 493 / 81

On to step 6:
81 goes into 493 6 times with a remainder of 7.
The number 6 becomes the next digit in our result. 
Result so far: 7526.0
The remainder is 7 after subtracting 486 from 493.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Going ahead to step 7:
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: 7526.0
Subtracting 0 from 70 leaves us 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 8:
If we divide 700 by 81, we get 8 and a remainder of 52.
Record the quotient 8 as the next digit in the result. 
Result so far: 7526.08
Subtract 648 from 700 to get 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 9:
81 goes into 520 6 times with a remainder of 34.
Record the quotient 6 as the next digit in the result. 
Result so far: 7526.086
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.

On to step 10:
If we divide 340 by 81, we get 4 and a remainder of 16.
The next digit of our result is 4. 
Result so far: 7526.0864
Deduct 324 from 340 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

On to step 11:
If we divide 160 by 81, we get 1 and a remainder of 79.
The next digit of our result is 1. 
Result so far: 7526.08641
If we subtract 81 from 160, 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.

Advancing to step 12:
790 divided by 81 is 9 with a remainder of 61.
The next digit of our result is 9. 
Result so far: 7526.086419
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.

Step 13:
If we divide 610 by 81, we get 7 and a remainder of 43.
Record the quotient 7 as the next digit in the result. 
Result so far: 7526.0864197
Deduct 567 from 610 and we're left 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.

Let's proceed to step 14:
81 can be fit into 430 5 times, resulting in a remainder of 25.
Use 5 as the next digit of our solution. 
Result so far: 7526.08641975
Subtracting 405 from 430 leaves us with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

The final result is 7526.08641975 with a remainder of 2.5e-08.