86901 ÷ 66 
The aim is to understand the frequency of 66 in 86901.

Step 1:
66 goes into 8 0 times with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Take the next digit (6) from the dividend and append it to 8, then repeat: 86 / 66

Moving on to step 2:
86 divided by 66 is 1 with a remainder of 20.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 66 from 86 to get 20.
Include the next digit (9) from the dividend after 20, then repeat: 209 / 66

Step 3:
The number 66 fits into 209 3 times, leaving a remainder of 11.
Use 3 as the next digit of our solution. 
Result so far: 13.0
If we subtract 198 from 209, we get 11.
Take the next digit (0) from the dividend and append it to 11, then repeat: 110 / 66

On to step 4:
The number 66 fits into 110 1 times, leaving a remainder of 44.
The number 1 becomes the next digit in our result. 
Result so far: 131.0
If we take 66 away from 110, we end up with 44.
Include the next digit (1) from the dividend after 44, then repeat: 441 / 66

On to step 5:
66 goes into 441 6 times with a remainder of 45.
Record the quotient 6 as the next digit in the result. 
Result so far: 1316.0
The remainder is 45 after subtracting 396 from 441.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Let's proceed to step 6:
66 goes into 450 6 times with a remainder of 54.
The number 6 becomes the next digit in our result. 
Result so far: 1316.6
Subtract 396 from 450 to get 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Let's proceed to step 7:
66 can be fit into 540 8 times, resulting in a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 1316.68
If we take 528 away from 540, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 8:
When dividing 120 by 66, we get 1 with a remainder of 54.
Write down 1 as next digit of the result. 
Result so far: 1316.681
Subtracting 66 from 120 leaves us with 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Advancing to step 9:
When dividing 540 by 66, we get 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 1316.6818
If we take 528 away from 540, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 10:
66 goes into 120 1 times with a remainder of 54.
The next digit of our result is 1. 
Result so far: 1316.68181
The remainder is 54 after subtracting 66 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Moving on to step 11:
The number 66 fits into 540 8 times, leaving a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 1316.681818
If we take 528 away from 540, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 12:
120 divided by 66 is 1 with a remainder of 54.
The number 1 becomes the next digit in our result. 
Result so far: 1316.6818181
If we take 66 away from 120, we end up with 54.
Since there are no more digits in the dividend, we add a zero to the remainder making it 540, and continue the process.

Advancing to step 13:
66 can be fit into 540 8 times, resulting in a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 1316.68181818
Subtracting 528 from 540 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

After the division, we end up with 1316.68181818 and a remainder of 1.2e-08.