668471 ÷ 80 
The aim is to understand the frequency of 80 in 668471.

Step 1:
The number 80 fits into 6 0 times, leaving a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 80

Let's proceed to step 2:
When dividing 66 by 80, we get 0 with a remainder of 66.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 66, we get 66.
Bring next digit (8) of the dividend behind the 66 and repeat the process: 668 / 80

Going ahead to step 3:
80 can be fit into 668 8 times, resulting in a remainder of 28.
Put 8 as the next digit of the answer. 
Result so far: 8.0
Deduct 640 from 668 and we're left with 28.
Bring next digit (4) of the dividend behind the 28 and repeat the process: 284 / 80

On to step 4:
When dividing 284 by 80, we get 3 with a remainder of 44.
The next digit of our result is 3. 
Result so far: 83.0
The remainder is 44 after subtracting 240 from 284.
Fetch the next digit (7) from the dividend, attach it to 44 and continue: 447 / 80

Moving on to step 5:
If we divide 447 by 80, we get 5 and a remainder of 47.
Write down 5 as next digit of the result. 
Result so far: 835.0
If we take 400 away from 447, we end up with 47.
Include the next digit (1) from the dividend after 47, then repeat: 471 / 80

Let's proceed to step 6:
80 goes into 471 5 times with a remainder of 71.
Write down 5 as next digit of the result. 
Result so far: 8355.0
Deduct 400 from 471 and we're left with 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Moving on to step 7:
710 divided by 80 is 8 with a remainder of 70.
Write down 8 as next digit of the result. 
Result so far: 8355.8
Subtracting 640 from 710 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.

Let's proceed to step 8:
If we divide 700 by 80, we get 8 and a remainder of 60.
The next digit of our result is 8. 
Result so far: 8355.88
Subtract 640 from 700 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.

Our division results in 8355.88 with a remaining 0.06.