We look at the division of 778808 by 81 
The aim is to understand the frequency of 81 in 778808.

Advancing to step 1:
The number 81 fits into 7 0 times, leaving a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Append the next digit (7) from the dividend to 7 and continue with: 77 / 81

Advancing to step 2:
The number 81 fits into 77 0 times, leaving a remainder of 77.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 77 and we're left with 77.
Fetch the next digit (8) from the dividend, attach it to 77 and continue: 778 / 81

Step 3:
778 divided by 81 is 9 with a remainder of 49.
Record the quotient 9 as the next digit in the result. 
Result so far: 9.0
Subtracting 729 from 778 leaves us with 49.
Take the next digit (8) from the dividend and append it to 49, then repeat: 498 / 81

Moving on to step 4:
When dividing 498 by 81, we get 6 with a remainder of 12.
The number 6 becomes the next digit in our result. 
Result so far: 96.0
The remainder is 12 after subtracting 486 from 498.
Include the next digit (0) from the dividend after 12, then repeat: 120 / 81

Let's proceed to step 5:
When dividing 120 by 81, we get 1 with a remainder of 39.
The number 1 becomes the next digit in our result. 
Result so far: 961.0
Deduct 81 from 120 and we're left with 39.
Fetch the next digit (8) from the dividend, attach it to 39 and continue: 398 / 81

On to step 6:
The number 81 fits into 398 4 times, leaving a remainder of 74.
Use 4 as the next digit of our solution. 
Result so far: 9614.0
Deduct 324 from 398 and we're left with 74.
Since there are no more digits in the dividend, we add a zero to the remainder making it 740, and continue the process.

Let's proceed to step 7:
The number 81 fits into 740 9 times, leaving a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 9614.9
Subtracting 729 from 740 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 8:
If we divide 110 by 81, we get 1 and a remainder of 29.
Use 1 as the next digit of our solution. 
Result so far: 9614.91
Deduct 81 from 110 and we're left with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Let's proceed to step 9:
290 divided by 81 is 3 with a remainder of 47.
Put 3 as the next digit of the answer. 
Result so far: 9614.913
Subtract 243 from 290 to get 47.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

Going ahead to step 10:
81 can be fit into 470 5 times, resulting in a remainder of 65.
Use 5 as the next digit of our solution. 
Result so far: 9614.9135
Subtract 405 from 470 to get 65.
Since there are no more digits in the dividend, we add a zero to the remainder making it 650, and continue the process.

Step 11:
When dividing 650 by 81, we get 8 with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 9614.91358
If we subtract 648 from 650, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 12:
If we divide 20 by 81, we get 0 and a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 9614.91358
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 13:
81 goes into 200 2 times with a remainder of 38.
Use 2 as the next digit of our solution. 
Result so far: 9614.9135802
If we take 162 away from 200, we end up with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

On to step 14:
If we divide 380 by 81, we get 4 and a remainder of 56.
The number 4 becomes the next digit in our result. 
Result so far: 9614.91358024
Subtracting 324 from 380 leaves us with 56.
Since there are no more digits in the dividend, we add a zero to the remainder making it 560, and continue the process.

The final result is 9614.91358024 with a remainder of 5.6e-08.