We look at the division of 229431 by 81 
The aim is to understand the frequency of 81 in 229431.

Let's proceed 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
If we subtract 0 from 2, we get 2.
Append the next digit (2) from the dividend to 2 and continue with: 22 / 81

Let's proceed to step 2:
22 divided by 81 is 0 with a remainder of 22.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 22, we get 22.
Include the next digit (9) from the dividend after 22, then repeat: 229 / 81

Step 3:
81 goes into 229 2 times with a remainder of 67.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 162 away from 229, we end up with 67.
Fetch the next digit (4) from the dividend, attach it to 67 and continue: 674 / 81

Going ahead to step 4:
When dividing 674 by 81, we get 8 with a remainder of 26.
The next digit of our result is 8. 
Result so far: 28.0
If we subtract 648 from 674, we get 26.
Append the next digit (3) from the dividend to 26 and continue with: 263 / 81

Going ahead to step 5:
263 divided by 81 is 3 with a remainder of 20.
Write down 3 as next digit of the result. 
Result so far: 283.0
Subtract 243 from 263 to get 20.
Bring next digit (1) of the dividend behind the 20 and repeat the process: 201 / 81

Advancing to step 6:
When dividing 201 by 81, we get 2 with a remainder of 39.
The next digit of our result is 2. 
Result so far: 2832.0
Subtract 162 from 201 to get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Going ahead to step 7:
The number 81 fits into 390 4 times, leaving a remainder of 66.
Record the quotient 4 as the next digit in the result. 
Result so far: 2832.4
Subtracting 324 from 390 leaves us with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Advancing to step 8:
660 divided by 81 is 8 with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 2832.48
Deduct 648 from 660 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 9:
When dividing 120 by 81, we get 1 with a remainder of 39.
Put 1 as the next digit of the answer. 
Result so far: 2832.481
If we take 81 away from 120, we end up with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 10:
When dividing 390 by 81, we get 4 with a remainder of 66.
The next digit of our result is 4. 
Result so far: 2832.4814
Deduct 324 from 390 and we're left with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Moving on to step 11:
When dividing 660 by 81, we get 8 with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 2832.48148
If we take 648 away from 660, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 12:
81 goes into 120 1 times with a remainder of 39.
Put 1 as the next digit of the answer. 
Result so far: 2832.481481
The remainder is 39 after subtracting 81 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Going ahead to step 13:
If we divide 390 by 81, we get 4 and a remainder of 66.
Write down 4 as next digit of the result. 
Result so far: 2832.4814814
If we take 324 away from 390, we end up with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Advancing to step 14:
The number 81 fits into 660 8 times, leaving a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 2832.48148148
If we take 648 away from 660, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final result is 2832.48148148 with a remainder of 1.2e-08.