We look at the division of 186191 by 66 
The aim is to understand the frequency of 66 in 186191.

On to step 1:
When dividing 1 by 66, we get 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 66

Going ahead to step 2:
When dividing 18 by 66, we get 0 with a remainder of 18.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 18, we get 18.
Take the next digit (6) from the dividend and append it to 18, then repeat: 186 / 66

Advancing to step 3:
66 goes into 186 2 times with a remainder of 54.
The next digit of our result is 2. 
Result so far: 2.0
Subtracting 132 from 186 leaves us with 54.
Bring next digit (1) of the dividend behind the 54 and repeat the process: 541 / 66

Advancing to step 4:
66 goes into 541 8 times with a remainder of 13.
Record the quotient 8 as the next digit in the result. 
Result so far: 28.0
Subtract 528 from 541 to get 13.
Bring next digit (9) of the dividend behind the 13 and repeat the process: 139 / 66

Moving on to step 5:
139 divided by 66 is 2 with a remainder of 7.
Record the quotient 2 as the next digit in the result. 
Result so far: 282.0
Subtract 132 from 139 to get 7.
Grab the next digit (1) from the dividend, add it to 7, then carry on: 71 / 66

Moving on to step 6:
When dividing 71 by 66, we get 1 with a remainder of 5.
Write down 1 as next digit of the result. 
Result so far: 2821.0
Subtract 66 from 71 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 7:
66 goes into 50 0 times with a remainder of 50.
Use 0 as the next digit of our solution. 
Result so far: 2821.0
If we subtract 0 from 50, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 8:
If we divide 500 by 66, we get 7 and a remainder of 38.
Record the quotient 7 as the next digit in the result. 
Result so far: 2821.07
Deduct 462 from 500 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Let's proceed to step 9:
66 can be fit into 380 5 times, resulting in a remainder of 50.
The next digit of our result is 5. 
Result so far: 2821.075
If we subtract 330 from 380, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Let's proceed to step 10:
The number 66 fits into 500 7 times, leaving a remainder of 38.
Use 7 as the next digit of our solution. 
Result so far: 2821.0757
The remainder is 38 after subtracting 462 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Moving on to step 11:
When dividing 380 by 66, we get 5 with a remainder of 50.
Use 5 as the next digit of our solution. 
Result so far: 2821.07575
Subtracting 330 from 380 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 12:
66 goes into 500 7 times with a remainder of 38.
Record the quotient 7 as the next digit in the result. 
Result so far: 2821.075757
Deduct 462 from 500 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

Step 13:
66 goes into 380 5 times with a remainder of 50.
The next digit of our result is 5. 
Result so far: 2821.0757575
Subtract 330 from 380 to get 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 14:
66 goes into 500 7 times with a remainder of 38.
Put 7 as the next digit of the answer. 
Result so far: 2821.07575757
If we subtract 462 from 500, we get 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

In conclusion, the division gives 2821.07575757 with a balance of 3.8e-08.