898865 divided by 81 
The aim is to understand the frequency of 81 in 898865.

On to step 1:
8 divided by 81 is 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Append the next digit (9) from the dividend to 8 and continue with: 89 / 81

Moving on to step 2:
When dividing 89 by 81, we get 1 with a remainder of 8.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
The remainder is 8 after subtracting 81 from 89.
Bring next digit (8) of the dividend behind the 8 and repeat the process: 88 / 81

On to step 3:
The number 81 fits into 88 1 times, leaving a remainder of 7.
The next digit of our result is 1. 
Result so far: 11.0
Subtract 81 from 88 to get 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 81

Moving on to step 4:
If we divide 78 by 81, we get 0 and a remainder of 78.
Write down 0 as next digit of the result. 
Result so far: 110.0
Deduct 0 from 78 and we're left with 78.
Grab the next digit (6) from the dividend, add it to 78, then carry on: 786 / 81

Moving on to step 5:
If we divide 786 by 81, we get 9 and a remainder of 57.
Write down 9 as next digit of the result. 
Result so far: 1109.0
The remainder is 57 after subtracting 729 from 786.
Include the next digit (5) from the dividend after 57, then repeat: 575 / 81

On to step 6:
When dividing 575 by 81, we get 7 with a remainder of 8.
Record the quotient 7 as the next digit in the result. 
Result so far: 11097.0
If we take 567 away from 575, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 7:
When dividing 80 by 81, we get 0 with a remainder of 80.
Write down 0 as next digit of the result. 
Result so far: 11097.0
If we take 0 away from 80, we end up with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

On to step 8:
When dividing 800 by 81, we get 9 with a remainder of 71.
The next digit of our result is 9. 
Result so far: 11097.09
Subtracting 729 from 800 leaves us with 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Step 9:
710 divided by 81 is 8 with a remainder of 62.
Use 8 as the next digit of our solution. 
Result so far: 11097.098
If we take 648 away from 710, we end up with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Going ahead to step 10:
81 can be fit into 620 7 times, resulting in a remainder of 53.
Record the quotient 7 as the next digit in the result. 
Result so far: 11097.0987
If we take 567 away from 620, we end up with 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Going ahead to step 11:
When dividing 530 by 81, we get 6 with a remainder of 44.
Write down 6 as next digit of the result. 
Result so far: 11097.09876
The remainder is 44 after subtracting 486 from 530.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Advancing to step 12:
If we divide 440 by 81, we get 5 and a remainder of 35.
The number 5 becomes the next digit in our result. 
Result so far: 11097.098765
Subtract 405 from 440 to get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Let's proceed to step 13:
81 goes into 350 4 times with a remainder of 26.
The number 4 becomes the next digit in our result. 
Result so far: 11097.0987654
If we take 324 away from 350, we end up with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Let's proceed to step 14:
260 divided by 81 is 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 11097.09876543
The remainder is 17 after subtracting 243 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

The quotient of the division is 11097.09876543, and the remainder is 1.7e-08.