We're dividing 239431 by 81 
The aim is to understand the frequency of 81 in 239431.

Going ahead to step 1:
When dividing 2 by 81, we get 0 with a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Grab the next digit (3) from the dividend, add it to 2, then carry on: 23 / 81

On to step 2:
The number 81 fits into 23 0 times, leaving a remainder of 23.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 23 after subtracting 0 from 23.
Include the next digit (9) from the dividend after 23, then repeat: 239 / 81

Let's proceed to step 3:
When dividing 239 by 81, we get 2 with a remainder of 77.
Write down 2 as next digit of the result. 
Result so far: 2.0
Deduct 162 from 239 and we're left with 77.
Take the next digit (4) from the dividend and append it to 77, then repeat: 774 / 81

Advancing to step 4:
774 divided by 81 is 9 with a remainder of 45.
The next digit of our result is 9. 
Result so far: 29.0
The remainder is 45 after subtracting 729 from 774.
Bring next digit (3) of the dividend behind the 45 and repeat the process: 453 / 81

Step 5:
453 divided by 81 is 5 with a remainder of 48.
The next digit of our result is 5. 
Result so far: 295.0
Subtract 405 from 453 to get 48.
Bring next digit (1) of the dividend behind the 48 and repeat the process: 481 / 81

On to step 6:
The number 81 fits into 481 5 times, leaving a remainder of 76.
The number 5 becomes the next digit in our result. 
Result so far: 2955.0
Subtracting 405 from 481 leaves us with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Let's proceed to step 7:
If we divide 760 by 81, we get 9 and a remainder of 31.
The number 9 becomes the next digit in our result. 
Result so far: 2955.9
If we take 729 away from 760, we end up with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Let's proceed to step 8:
81 can be fit into 310 3 times, resulting in a remainder of 67.
Put 3 as the next digit of the answer. 
Result so far: 2955.93
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.

Advancing to step 9:
The number 81 fits into 670 8 times, leaving a remainder of 22.
Put 8 as the next digit of the answer. 
Result so far: 2955.938
Subtract 648 from 670 to get 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:
81 can be fit into 220 2 times, resulting in a remainder of 58.
Use 2 as the next digit of our solution. 
Result so far: 2955.9382
Deduct 162 from 220 and we're left with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 11:
The number 81 fits into 580 7 times, leaving a remainder of 13.
The next digit of our result is 7. 
Result so far: 2955.93827
The remainder is 13 after subtracting 567 from 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 12:
130 divided by 81 is 1 with a remainder of 49.
Write down 1 as next digit of the result. 
Result so far: 2955.938271
If we subtract 81 from 130, we get 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Step 13:
The number 81 fits into 490 6 times, leaving a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 2955.9382716
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.

On to step 14:
40 divided by 81 is 0 with a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 2955.9382716
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 2955.9382716 with a remaining 4e-08.