We look at the division of 811931 by 80 
The aim is to understand the frequency of 80 in 811931.

On to step 1:
80 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Grab the next digit (1) from the dividend, add it to 8, then carry on: 81 / 80

Moving on to step 2:
80 goes into 81 1 times with a remainder of 1.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtract 80 from 81 to get 1.
Grab the next digit (1) from the dividend, add it to 1, then carry on: 11 / 80

Moving on to step 3:
The number 80 fits into 11 0 times, leaving a remainder of 11.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
If we take 0 away from 11, we end up with 11.
Take the next digit (9) from the dividend and append it to 11, then repeat: 119 / 80

Going ahead to step 4:
80 goes into 119 1 times with a remainder of 39.
Record the quotient 1 as the next digit in the result. 
Result so far: 101.0
The remainder is 39 after subtracting 80 from 119.
Fetch the next digit (3) from the dividend, attach it to 39 and continue: 393 / 80

Let's proceed to step 5:
80 goes into 393 4 times with a remainder of 73.
Write down 4 as next digit of the result. 
Result so far: 1014.0
If we subtract 320 from 393, we get 73.
Include the next digit (1) from the dividend after 73, then repeat: 731 / 80

On to step 6:
80 goes into 731 9 times with a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 10149.0
Subtracting 720 from 731 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.

Let's proceed to step 7:
80 goes into 110 1 times with a remainder of 30.
Put 1 as the next digit of the answer. 
Result so far: 10149.1
Subtracting 80 from 110 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 8:
The number 80 fits into 300 3 times, leaving a remainder of 60.
Write down 3 as next digit of the result. 
Result so far: 10149.13
If we take 240 away from 300, we end up with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

On to step 9:
The number 80 fits into 600 7 times, leaving a remainder of 40.
The next digit of our result is 7. 
Result so far: 10149.137
Subtract 560 from 600 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 10:
The number 80 fits into 400 5 times, leaving a remainder of 0.
The next digit of our result is 5. 
Result so far: 10149.1375
Subtract 400 from 400 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 11:
0 divided by 80 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 10149.1375
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 12:
If we divide 0 by 80, we get 0 and a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 10149.1375
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 10149.1375, with a leftover of 0.0.