581581 ÷ 80 
The aim is to understand the frequency of 80 in 581581.

Advancing to step 1:
5 divided by 80 is 0 with a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Take the next digit (8) from the dividend and append it to 5, then repeat: 58 / 80

Advancing to step 2:
80 can be fit into 58 0 times, resulting in a remainder of 58.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 58 after subtracting 0 from 58.
Grab the next digit (1) from the dividend, add it to 58, then carry on: 581 / 80

On to step 3:
The number 80 fits into 581 7 times, leaving a remainder of 21.
Write down 7 as next digit of the result. 
Result so far: 7.0
If we take 560 away from 581, we end up with 21.
Bring next digit (5) of the dividend behind the 21 and repeat the process: 215 / 80

Moving on to step 4:
If we divide 215 by 80, we get 2 and a remainder of 55.
The number 2 becomes the next digit in our result. 
Result so far: 72.0
Deduct 160 from 215 and we're left with 55.
Take the next digit (8) from the dividend and append it to 55, then repeat: 558 / 80

Moving on to step 5:
558 divided by 80 is 6 with a remainder of 78.
The number 6 becomes the next digit in our result. 
Result so far: 726.0
Deduct 480 from 558 and we're left with 78.
Append the next digit (1) from the dividend to 78 and continue with: 781 / 80

Advancing to step 6:
781 divided by 80 is 9 with a remainder of 61.
Write down 9 as next digit of the result. 
Result so far: 7269.0
Subtract 720 from 781 to get 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

Let's proceed to step 7:
80 can be fit into 610 7 times, resulting in a remainder of 50.
Use 7 as the next digit of our solution. 
Result so far: 7269.7
Subtracting 560 from 610 leaves us 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.

Advancing to step 8:
If we divide 500 by 80, we get 6 and a remainder of 20.
Use 6 as the next digit of our solution. 
Result so far: 7269.76
Deduct 480 from 500 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.

Let's proceed to step 9:
If we divide 200 by 80, we get 2 and a remainder of 40.
Use 2 as the next digit of our solution. 
Result so far: 7269.762
Subtract 160 from 200 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:
If we divide 400 by 80, we get 5 and a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 7269.7625
If we subtract 400 from 400, we 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.

Step 11:
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: 7269.7625
If we subtract 0 from 0, we 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.

Let's proceed to step 12:
If we divide 0 by 80, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 7269.7625
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 7269.7625 with a remainder of 0.0.