Let's divide 66015741 by 81
The aim is to understand the frequency of 81 in 66015741.

Moving on to step 1:
81 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 81

On to step 2:
The number 81 fits into 66 0 times, leaving a remainder of 66.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 66, we get 66.
Include the next digit (0) from the dividend after 66, then repeat: 660 / 81

On to step 3:
660 divided by 81 is 8 with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 8.0
If we take 648 away from 660, we end up with 12.
Append the next digit (1) from the dividend to 12 and continue with: 121 / 81

On to step 4:
When dividing 121 by 81, we get 1 with a remainder of 40.
Record the quotient 1 as the next digit in the result. 
Result so far: 81.0
The remainder is 40 after subtracting 81 from 121.
Append the next digit (5) from the dividend to 40 and continue with: 405 / 81

Let's proceed to step 5:
When dividing 405 by 81, we get 5 with a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 815.0
Subtract 405 from 405 to get 0.
Grab the next digit (7) from the dividend, add it to 0, then carry on: 7 / 81

Going ahead to step 6:
7 divided by 81 is 0 with a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 8150.0
Deduct 0 from 7 and we're left with 7.
Bring next digit (4) of the dividend behind the 7 and repeat the process: 74 / 81

Advancing to step 7:
81 goes into 74 0 times with a remainder of 74.
Put 0 as the next digit of the answer. 
Result so far: 81500.0
If we take 0 away from 74, we end up with 74.
Take the next digit (1) from the dividend and append it to 74, then repeat: 741 / 81

Advancing to step 8:
If we divide 741 by 81, we get 9 and a remainder of 12.
Record the quotient 9 as the next digit in the result. 
Result so far: 815009.0
Subtract 729 from 741 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 9:
The number 81 fits into 120 1 times, leaving a remainder of 39.
Use 1 as the next digit of our solution. 
Result so far: 815009.1
Deduct 81 from 120 and we're left 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.

Step 10:
When dividing 390 by 81, we get 4 with a remainder of 66.
Use 4 as the next digit of our solution. 
Result so far: 815009.14
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 11:
81 can be fit into 660 8 times, resulting in a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 815009.148
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.

Advancing to step 12:
81 can be fit into 120 1 times, resulting in a remainder of 39.
Put 1 as the next digit of the answer. 
Result so far: 815009.1481
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 13:
81 can be fit into 390 4 times, resulting in a remainder of 66.
The next digit of our result is 4. 
Result so far: 815009.14814
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.

Let's proceed to step 14:
When dividing 660 by 81, we get 8 with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 815009.148148
Subtract 648 from 660 to get 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 15:
When dividing 120 by 81, we get 1 with a remainder of 39.
Use 1 as the next digit of our solution. 
Result so far: 815009.1481481
If we subtract 81 from 120, we 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.

Moving on to step 16:
If we divide 390 by 81, we get 4 and a remainder of 66.
The number 4 becomes the next digit in our result. 
Result so far: 815009.14814814
If we subtract 324 from 390, we get 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Our division results in 815009.14814814 with a remaining 6.6e-08.