828395 ÷ 66 
The aim is to understand the frequency of 66 in 828395.

Step 1:
If we divide 8 by 66, we get 0 and a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Take the next digit (2) from the dividend and append it to 8, then repeat: 82 / 66

Advancing to step 2:
The number 66 fits into 82 1 times, leaving a remainder of 16.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 16 after subtracting 66 from 82.
Append the next digit (8) from the dividend to 16 and continue with: 168 / 66

Step 3:
168 divided by 66 is 2 with a remainder of 36.
The number 2 becomes the next digit in our result. 
Result so far: 12.0
Deduct 132 from 168 and we're left with 36.
Bring next digit (3) of the dividend behind the 36 and repeat the process: 363 / 66

Step 4:
If we divide 363 by 66, we get 5 and a remainder of 33.
Use 5 as the next digit of our solution. 
Result so far: 125.0
Deduct 330 from 363 and we're left with 33.
Fetch the next digit (9) from the dividend, attach it to 33 and continue: 339 / 66

Going ahead to step 5:
66 can be fit into 339 5 times, resulting in a remainder of 9.
The next digit of our result is 5. 
Result so far: 1255.0
Subtract 330 from 339 to get 9.
Include the next digit (5) from the dividend after 9, then repeat: 95 / 66

Moving on to step 6:
95 divided by 66 is 1 with a remainder of 29.
The next digit of our result is 1. 
Result so far: 12551.0
Subtracting 66 from 95 leaves us with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Let's proceed to step 7:
If we divide 290 by 66, we get 4 and a remainder of 26.
Put 4 as the next digit of the answer. 
Result so far: 12551.4
Subtract 264 from 290 to get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Going ahead to step 8:
The number 66 fits into 260 3 times, leaving a remainder of 62.
Record the quotient 3 as the next digit in the result. 
Result so far: 12551.43
The remainder is 62 after subtracting 198 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Step 9:
620 divided by 66 is 9 with a remainder of 26.
The next digit of our result is 9. 
Result so far: 12551.439
Subtracting 594 from 620 leaves us with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

On to step 10:
The number 66 fits into 260 3 times, leaving a remainder of 62.
The number 3 becomes the next digit in our result. 
Result so far: 12551.4393
If we subtract 198 from 260, we get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Let's proceed to step 11:
When dividing 620 by 66, we get 9 with a remainder of 26.
Use 9 as the next digit of our solution. 
Result so far: 12551.43939
Subtracting 594 from 620 leaves us with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Moving on to step 12:
If we divide 260 by 66, we get 3 and a remainder of 62.
Put 3 as the next digit of the answer. 
Result so far: 12551.439393
Subtracting 198 from 260 leaves us with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Going ahead to step 13:
620 divided by 66 is 9 with a remainder of 26.
The number 9 becomes the next digit in our result. 
Result so far: 12551.4393939
If we subtract 594 from 620, we get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Step 14:
260 divided by 66 is 3 with a remainder of 62.
The number 3 becomes the next digit in our result. 
Result so far: 12551.43939393
Subtract 198 from 260 to get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

The final outcome is 12551.43939393, with a leftover of 6.2e-08.