We look at the division of 535236 by 81 
The aim is to understand the frequency of 81 in 535236.

Step 1:
If we divide 5 by 81, we get 0 and a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Take the next digit (3) from the dividend and append it to 5, then repeat: 53 / 81

Let's proceed to step 2:
If we divide 53 by 81, we get 0 and a remainder of 53.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 53, we end up with 53.
Include the next digit (5) from the dividend after 53, then repeat: 535 / 81

Moving on to step 3:
535 divided by 81 is 6 with a remainder of 49.
Record the quotient 6 as the next digit in the result. 
Result so far: 6.0
Subtract 486 from 535 to get 49.
Include the next digit (2) from the dividend after 49, then repeat: 492 / 81

Let's proceed to step 4:
492 divided by 81 is 6 with a remainder of 6.
Use 6 as the next digit of our solution. 
Result so far: 66.0
Deduct 486 from 492 and we're left with 6.
Fetch the next digit (3) from the dividend, attach it to 6 and continue: 63 / 81

Step 5:
The number 81 fits into 63 0 times, leaving a remainder of 63.
Write down 0 as next digit of the result. 
Result so far: 660.0
Subtract 0 from 63 to get 63.
Append the next digit (6) from the dividend to 63 and continue with: 636 / 81

Going ahead to step 6:
When dividing 636 by 81, we get 7 with a remainder of 69.
Use 7 as the next digit of our solution. 
Result so far: 6607.0
Deduct 567 from 636 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.

On to step 7:
690 divided by 81 is 8 with a remainder of 42.
The number 8 becomes the next digit in our result. 
Result so far: 6607.8
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.

Going ahead to step 8:
420 divided by 81 is 5 with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 6607.85
If we take 405 away from 420, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 9:
When dividing 150 by 81, we get 1 with a remainder of 69.
Write down 1 as next digit of the result. 
Result so far: 6607.851
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 10:
690 divided by 81 is 8 with a remainder of 42.
The number 8 becomes the next digit in our result. 
Result so far: 6607.8518
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 11:
81 can be fit into 420 5 times, resulting in a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 6607.85185
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.

Let's proceed to step 12:
When dividing 150 by 81, we get 1 with a remainder of 69.
The number 1 becomes the next digit in our result. 
Result so far: 6607.851851
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.

Let's proceed to step 13:
690 divided by 81 is 8 with a remainder of 42.
The number 8 becomes the next digit in our result. 
Result so far: 6607.8518518
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.

Let's proceed to step 14:
81 can be fit into 420 5 times, resulting in a remainder of 15.
The next digit of our result is 5. 
Result so far: 6607.85185185
Subtract 405 from 420 to 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.

Our division results in 6607.85185185 with a remaining 1.5e-08.