We look at the division of 726344 by 81 
The aim is to understand the frequency of 81 in 726344.

Going ahead to step 1:
The number 81 fits into 7 0 times, leaving a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Grab the next digit (2) from the dividend, add it to 7, then carry on: 72 / 81

Advancing to step 2:
When dividing 72 by 81, we get 0 with a remainder of 72.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 72, we end up with 72.
Include the next digit (6) from the dividend after 72, then repeat: 726 / 81

Step 3:
If we divide 726 by 81, we get 8 and a remainder of 78.
Use 8 as the next digit of our solution. 
Result so far: 8.0
Subtracting 648 from 726 leaves us with 78.
Bring next digit (3) of the dividend behind the 78 and repeat the process: 783 / 81

Moving on to step 4:
The number 81 fits into 783 9 times, leaving a remainder of 54.
Use 9 as the next digit of our solution. 
Result so far: 89.0
Subtracting 729 from 783 leaves us with 54.
Append the next digit (4) from the dividend to 54 and continue with: 544 / 81

Moving on to step 5:
81 goes into 544 6 times with a remainder of 58.
The next digit of our result is 6. 
Result so far: 896.0
Deduct 486 from 544 and we're left with 58.
Include the next digit (4) from the dividend after 58, then repeat: 584 / 81

Moving on to step 6:
81 can be fit into 584 7 times, resulting in a remainder of 17.
Put 7 as the next digit of the answer. 
Result so far: 8967.0
The remainder is 17 after subtracting 567 from 584.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 7:
The number 81 fits into 170 2 times, leaving a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 8967.2
The remainder is 8 after subtracting 162 from 170.
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 8:
The number 81 fits into 80 0 times, leaving a remainder of 80.
Use 0 as the next digit of our solution. 
Result so far: 8967.2
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.

Advancing to step 9:
When dividing 800 by 81, we get 9 with a remainder of 71.
The number 9 becomes the next digit in our result. 
Result so far: 8967.209
Deduct 729 from 800 and we're left 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.

On to step 10:
710 divided by 81 is 8 with a remainder of 62.
The next digit of our result is 8. 
Result so far: 8967.2098
The remainder is 62 after subtracting 648 from 710.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

On to step 11:
If we divide 620 by 81, we get 7 and a remainder of 53.
Record the quotient 7 as the next digit in the result. 
Result so far: 8967.20987
Subtract 567 from 620 to get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Let's proceed to step 12:
The number 81 fits into 530 6 times, leaving a remainder of 44.
Write down 6 as next digit of the result. 
Result so far: 8967.209876
Deduct 486 from 530 and we're left with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Let's proceed to step 13:
The number 81 fits into 440 5 times, leaving a remainder of 35.
Use 5 as the next digit of our solution. 
Result so far: 8967.2098765
Deduct 405 from 440 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Step 14:
81 can be fit into 350 4 times, resulting in a remainder of 26.
Use 4 as the next digit of our solution. 
Result so far: 8967.20987654
Subtract 324 from 350 to get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

The final result is 8967.20987654 with a remainder of 2.6e-08.