39511227 divided by 399 
The aim is to understand the frequency of 399 in 39511227.

On to step 1:
399 goes into 3 0 times with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 399

Advancing to step 2:
39 divided by 399 is 0 with a remainder of 39.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 39, we get 39.
Bring next digit (5) of the dividend behind the 39 and repeat the process: 395 / 399

Let's proceed to step 3:
399 can be fit into 395 0 times, resulting in a remainder of 395.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 395 after subtracting 0 from 395.
Append the next digit (1) from the dividend to 395 and continue with: 3951 / 399

Going ahead to step 4:
399 goes into 3951 9 times with a remainder of 360.
The next digit of our result is 9. 
Result so far: 9.0
If we take 3591 away from 3951, we end up with 360.
Include the next digit (1) from the dividend after 360, then repeat: 3601 / 399

Step 5:
399 can be fit into 3601 9 times, resulting in a remainder of 10.
The number 9 becomes the next digit in our result. 
Result so far: 99.0
Subtracting 3591 from 3601 leaves us with 10.
Grab the next digit (2) from the dividend, add it to 10, then carry on: 102 / 399

Advancing to step 6:
399 can be fit into 102 0 times, resulting in a remainder of 102.
Write down 0 as next digit of the result. 
Result so far: 990.0
Deduct 0 from 102 and we're left with 102.
Include the next digit (2) from the dividend after 102, then repeat: 1022 / 399

Going ahead to step 7:
1022 divided by 399 is 2 with a remainder of 224.
Put 2 as the next digit of the answer. 
Result so far: 9902.0
Deduct 798 from 1022 and we're left with 224.
Take the next digit (7) from the dividend and append it to 224, then repeat: 2247 / 399

Let's proceed to step 8:
When dividing 2247 by 399, we get 5 with a remainder of 252.
Record the quotient 5 as the next digit in the result. 
Result so far: 99025.0
Deduct 1995 from 2247 and we're left with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

Let's proceed to step 9:
2520 divided by 399 is 6 with a remainder of 126.
Record the quotient 6 as the next digit in the result. 
Result so far: 99025.6
Deduct 2394 from 2520 and we're left with 126.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1260, and continue the process.

Step 10:
The number 399 fits into 1260 3 times, leaving a remainder of 63.
Put 3 as the next digit of the answer. 
Result so far: 99025.63
Deduct 1197 from 1260 and we're left with 63.
Since there are no more digits in the dividend, we add a zero to the remainder making it 630, and continue the process.

Step 11:
The number 399 fits into 630 1 times, leaving a remainder of 231.
Record the quotient 1 as the next digit in the result. 
Result so far: 99025.631
If we subtract 399 from 630, we get 231.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2310, and continue the process.

Let's proceed to step 12:
The number 399 fits into 2310 5 times, leaving a remainder of 315.
The next digit of our result is 5. 
Result so far: 99025.6315
Subtracting 1995 from 2310 leaves us with 315.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3150, and continue the process.

Step 13:
399 can be fit into 3150 7 times, resulting in a remainder of 357.
The next digit of our result is 7. 
Result so far: 99025.63157
If we take 2793 away from 3150, we end up with 357.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3570, and continue the process.

Going ahead to step 14:
399 can be fit into 3570 8 times, resulting in a remainder of 378.
The next digit of our result is 8. 
Result so far: 99025.631578
Deduct 3192 from 3570 and we're left with 378.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3780, and continue the process.

Advancing to step 15:
399 can be fit into 3780 9 times, resulting in a remainder of 189.
Write down 9 as next digit of the result. 
Result so far: 99025.6315789
If we subtract 3591 from 3780, we get 189.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1890, and continue the process.

On to step 16:
If we divide 1890 by 399, we get 4 and a remainder of 294.
Use 4 as the next digit of our solution. 
Result so far: 99025.63157894
The remainder is 294 after subtracting 1596 from 1890.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2940, and continue the process.

The final outcome is 99025.63157894, with a leftover of 2.94e-07.