We divide 397989 by 80
The aim is to understand the frequency of 80 in 397989.

On to step 1:
The number 80 fits into 3 0 times, leaving a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 80

On to step 2:
39 divided by 80 is 0 with a remainder of 39.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 39 after subtracting 0 from 39.
Grab the next digit (7) from the dividend, add it to 39, then carry on: 397 / 80

On to step 3:
397 divided by 80 is 4 with a remainder of 77.
Record the quotient 4 as the next digit in the result. 
Result so far: 4.0
Subtracting 320 from 397 leaves us with 77.
Append the next digit (9) from the dividend to 77 and continue with: 779 / 80

Going ahead to step 4:
The number 80 fits into 779 9 times, leaving a remainder of 59.
The next digit of our result is 9. 
Result so far: 49.0
The remainder is 59 after subtracting 720 from 779.
Take the next digit (8) from the dividend and append it to 59, then repeat: 598 / 80

Advancing to step 5:
598 divided by 80 is 7 with a remainder of 38.
The number 7 becomes the next digit in our result. 
Result so far: 497.0
If we subtract 560 from 598, we get 38.
Fetch the next digit (9) from the dividend, attach it to 38 and continue: 389 / 80

Let's proceed to step 6:
80 goes into 389 4 times with a remainder of 69.
The number 4 becomes the next digit in our result. 
Result so far: 4974.0
If we subtract 320 from 389, we get 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Let's proceed to step 7:
690 divided by 80 is 8 with a remainder of 50.
Write down 8 as next digit of the result. 
Result so far: 4974.8
If we take 640 away from 690, we end up with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Step 8:
80 goes into 500 6 times with a remainder of 20.
The number 6 becomes the next digit in our result. 
Result so far: 4974.86
The remainder is 20 after subtracting 480 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 9:
200 divided by 80 is 2 with a remainder of 40.
Use 2 as the next digit of our solution. 
Result so far: 4974.862
Subtracting 160 from 200 leaves us 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.

On to step 10:
The number 80 fits into 400 5 times, leaving a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 4974.8625
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.

Advancing to step 11:
When dividing 0 by 80, we get 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 4974.8625
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.

Moving on to step 12:
80 goes into 0 0 times with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 4974.8625
Subtract 0 from 0 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.

The final result is 4974.8625 with a remainder of 0.0.