859399 divided by 80 
The aim is to understand the frequency of 80 in 859399.

On 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
Subtract 0 from 8 to get 8.
Grab the next digit (5) from the dividend, add it to 8, then carry on: 85 / 80

On to step 2:
If we divide 85 by 80, we get 1 and a remainder of 5.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we take 80 away from 85, we end up with 5.
Append the next digit (9) from the dividend to 5 and continue with: 59 / 80

On to step 3:
When dividing 59 by 80, we get 0 with a remainder of 59.
Write down 0 as next digit of the result. 
Result so far: 10.0
If we subtract 0 from 59, we get 59.
Grab the next digit (3) from the dividend, add it to 59, then carry on: 593 / 80

Going ahead to step 4:
The number 80 fits into 593 7 times, leaving a remainder of 33.
Write down 7 as next digit of the result. 
Result so far: 107.0
Deduct 560 from 593 and we're left with 33.
Append the next digit (9) from the dividend to 33 and continue with: 339 / 80

On to step 5:
80 goes into 339 4 times with a remainder of 19.
Use 4 as the next digit of our solution. 
Result so far: 1074.0
Subtract 320 from 339 to get 19.
Bring next digit (9) of the dividend behind the 19 and repeat the process: 199 / 80

On to step 6:
199 divided by 80 is 2 with a remainder of 39.
Use 2 as the next digit of our solution. 
Result so far: 10742.0
If we subtract 160 from 199, 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.

Step 7:
80 goes into 390 4 times with a remainder of 70.
The next digit of our result is 4. 
Result so far: 10742.4
Subtracting 320 from 390 leaves us with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Advancing to step 8:
80 can be fit into 700 8 times, resulting in a remainder of 60.
The number 8 becomes the next digit in our result. 
Result so far: 10742.48
If we subtract 640 from 700, we 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.

Moving on to step 9:
80 goes into 600 7 times with a remainder of 40.
The number 7 becomes the next digit in our result. 
Result so far: 10742.487
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.

Moving on to step 10:
If we divide 400 by 80, we get 5 and a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 10742.4875
The remainder is 0 after subtracting 400 from 400.
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:
When dividing 0 by 80, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 10742.4875
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.

Let's proceed to step 12:
The number 80 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 10742.4875
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.

The final result is 10742.4875 with a remainder of 0.0.