We're dividing 639377 by 99 
The aim is to understand the frequency of 99 in 639377.

On to step 1:
6 divided by 99 is 0 with a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Fetch the next digit (3) from the dividend, attach it to 6 and continue: 63 / 99

Step 2:
When dividing 63 by 99, we get 0 with a remainder of 63.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 63 after subtracting 0 from 63.
Append the next digit (9) from the dividend to 63 and continue with: 639 / 99

Step 3:
If we divide 639 by 99, we get 6 and a remainder of 45.
The number 6 becomes the next digit in our result. 
Result so far: 6.0
Subtract 594 from 639 to get 45.
Take the next digit (3) from the dividend and append it to 45, then repeat: 453 / 99

Step 4:
99 goes into 453 4 times with a remainder of 57.
The next digit of our result is 4. 
Result so far: 64.0
Deduct 396 from 453 and we're left with 57.
Bring next digit (7) of the dividend behind the 57 and repeat the process: 577 / 99

Step 5:
99 can be fit into 577 5 times, resulting in a remainder of 82.
Record the quotient 5 as the next digit in the result. 
Result so far: 645.0
Subtracting 495 from 577 leaves us with 82.
Fetch the next digit (7) from the dividend, attach it to 82 and continue: 827 / 99

Let's proceed to step 6:
The number 99 fits into 827 8 times, leaving a remainder of 35.
Write down 8 as next digit of the result. 
Result so far: 6458.0
Subtract 792 from 827 to get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Step 7:
99 can be fit into 350 3 times, resulting in a remainder of 53.
The next digit of our result is 3. 
Result so far: 6458.3
Deduct 297 from 350 and we're left with 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

On to step 8:
When dividing 530 by 99, we get 5 with a remainder of 35.
The number 5 becomes the next digit in our result. 
Result so far: 6458.35
If we subtract 495 from 530, we get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Going ahead to step 9:
If we divide 350 by 99, we get 3 and a remainder of 53.
The number 3 becomes the next digit in our result. 
Result so far: 6458.353
The remainder is 53 after subtracting 297 from 350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Going ahead to step 10:
530 divided by 99 is 5 with a remainder of 35.
Record the quotient 5 as the next digit in the result. 
Result so far: 6458.3535
The remainder is 35 after subtracting 495 from 530.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Let's proceed to step 11:
When dividing 350 by 99, we get 3 with a remainder of 53.
Use 3 as the next digit of our solution. 
Result so far: 6458.35353
Deduct 297 from 350 and we're left with 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Going ahead to step 12:
The number 99 fits into 530 5 times, leaving a remainder of 35.
The next digit of our result is 5. 
Result so far: 6458.353535
Deduct 495 from 530 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Moving on to step 13:
If we divide 350 by 99, we get 3 and a remainder of 53.
The number 3 becomes the next digit in our result. 
Result so far: 6458.3535353
If we subtract 297 from 350, we get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Step 14:
If we divide 530 by 99, we get 5 and a remainder of 35.
The next digit of our result is 5. 
Result so far: 6458.35353535
The remainder is 35 after subtracting 495 from 530.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

The final result is 6458.35353535 with a remainder of 3.5e-08.