817251 ÷ 80 
The aim is to understand the frequency of 80 in 817251.

Let's proceed to step 1:
If we divide 8 by 80, we get 0 and a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 80

Advancing to step 2:
81 divided by 80 is 1 with a remainder of 1.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 80 from 81, we get 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 80

Going ahead to step 3:
80 goes into 17 0 times with a remainder of 17.
Put 0 as the next digit of the answer. 
Result so far: 10.0
The remainder is 17 after subtracting 0 from 17.
Include the next digit (2) from the dividend after 17, then repeat: 172 / 80

Moving on to step 4:
172 divided by 80 is 2 with a remainder of 12.
Put 2 as the next digit of the answer. 
Result so far: 102.0
If we take 160 away from 172, we end up with 12.
Bring next digit (5) of the dividend behind the 12 and repeat the process: 125 / 80

Advancing to step 5:
80 goes into 125 1 times with a remainder of 45.
The next digit of our result is 1. 
Result so far: 1021.0
If we subtract 80 from 125, we get 45.
Bring next digit (1) of the dividend behind the 45 and repeat the process: 451 / 80

Let's proceed to step 6:
451 divided by 80 is 5 with a remainder of 51.
The next digit of our result is 5. 
Result so far: 10215.0
Subtract 400 from 451 to get 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Advancing to step 7:
When dividing 510 by 80, we get 6 with a remainder of 30.
Write down 6 as next digit of the result. 
Result so far: 10215.6
If we subtract 480 from 510, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Advancing to step 8:
When dividing 300 by 80, we get 3 with a remainder of 60.
The next digit of our result is 3. 
Result so far: 10215.63
Subtract 240 from 300 to get 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:
If we divide 600 by 80, we get 7 and a remainder of 40.
The next digit of our result is 7. 
Result so far: 10215.637
If we take 560 away from 600, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 10:
When dividing 400 by 80, we get 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 10215.6375
Deduct 400 from 400 and we're left 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.

Step 11:
The number 80 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 10215.6375
Deduct 0 from 0 and we're left 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.

Let's proceed to step 12:
0 divided by 80 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 10215.6375
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 10215.6375 with a remaining 0.0.