We divide 813900 by 66
The aim is to understand the frequency of 66 in 813900.

Step 1:
When dividing 8 by 66, we get 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 66

Moving on to step 2:
The number 66 fits into 81 1 times, leaving a remainder of 15.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 15 after subtracting 66 from 81.
Append the next digit (3) from the dividend to 15 and continue with: 153 / 66

Advancing to step 3:
66 can be fit into 153 2 times, resulting in a remainder of 21.
The next digit of our result is 2. 
Result so far: 12.0
The remainder is 21 after subtracting 132 from 153.
Bring next digit (9) of the dividend behind the 21 and repeat the process: 219 / 66

Let's proceed to step 4:
66 goes into 219 3 times with a remainder of 21.
The next digit of our result is 3. 
Result so far: 123.0
The remainder is 21 after subtracting 198 from 219.
Include the next digit (0) from the dividend after 21, then repeat: 210 / 66

Advancing to step 5:
66 goes into 210 3 times with a remainder of 12.
The next digit of our result is 3. 
Result so far: 1233.0
If we subtract 198 from 210, we get 12.
Bring next digit (0) of the dividend behind the 12 and repeat the process: 120 / 66

On to step 6:
66 goes into 120 1 times with a remainder of 54.
Put 1 as the next digit of the answer. 
Result so far: 12331.0
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.

Moving on to step 7:
66 goes into 540 8 times with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 12331.8
Deduct 528 from 540 and we're left 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.

Moving on to step 8:
66 can be fit into 120 1 times, resulting in a remainder of 54.
Record the quotient 1 as the next digit in the result. 
Result so far: 12331.81
If we subtract 66 from 120, we 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.

Moving on to step 9:
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: 12331.818
Subtract 528 from 540 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 10:
When dividing 120 by 66, we get 1 with a remainder of 54.
Use 1 as the next digit of our solution. 
Result so far: 12331.8181
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.

Moving on to step 11:
When dividing 540 by 66, we get 8 with a remainder of 12.
The next digit of our result is 8. 
Result so far: 12331.81818
If we subtract 528 from 540, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 12:
The number 66 fits into 120 1 times, leaving a remainder of 54.
The next digit of our result is 1. 
Result so far: 12331.818181
Subtract 66 from 120 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.

Advancing to step 13:
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: 12331.8181818
If we subtract 528 from 540, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 14:
The number 66 fits into 120 1 times, leaving a remainder of 54.
Use 1 as the next digit of our solution. 
Result so far: 12331.81818181
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.

Our division results in 12331.81818181 with a remaining 5.4e-08.