We're dividing 85918254 by 399 
The aim is to understand the frequency of 399 in 85918254.

Step 1:
The number 399 fits into 8 0 times, leaving a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Take the next digit (5) from the dividend and append it to 8, then repeat: 85 / 399

On to step 2:
399 goes into 85 0 times with a remainder of 85.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 85 and we're left with 85.
Bring next digit (9) of the dividend behind the 85 and repeat the process: 859 / 399

Step 3:
When dividing 859 by 399, we get 2 with a remainder of 61.
Put 2 as the next digit of the answer. 
Result so far: 2.0
The remainder is 61 after subtracting 798 from 859.
Append the next digit (1) from the dividend to 61 and continue with: 611 / 399

Let's proceed to step 4:
399 can be fit into 611 1 times, resulting in a remainder of 212.
Use 1 as the next digit of our solution. 
Result so far: 21.0
Deduct 399 from 611 and we're left with 212.
Take the next digit (8) from the dividend and append it to 212, then repeat: 2128 / 399

On to step 5:
399 goes into 2128 5 times with a remainder of 133.
The next digit of our result is 5. 
Result so far: 215.0
Subtract 1995 from 2128 to get 133.
Take the next digit (2) from the dividend and append it to 133, then repeat: 1332 / 399

Advancing to step 6:
1332 divided by 399 is 3 with a remainder of 135.
Use 3 as the next digit of our solution. 
Result so far: 2153.0
If we take 1197 away from 1332, we end up with 135.
Fetch the next digit (5) from the dividend, attach it to 135 and continue: 1355 / 399

Advancing to step 7:
When dividing 1355 by 399, we get 3 with a remainder of 158.
The next digit of our result is 3. 
Result so far: 21533.0
If we subtract 1197 from 1355, we get 158.
Bring next digit (4) of the dividend behind the 158 and repeat the process: 1584 / 399

On to step 8:
1584 divided by 399 is 3 with a remainder of 387.
Record the quotient 3 as the next digit in the result. 
Result so far: 215333.0
Subtract 1197 from 1584 to get 387.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3870, and continue the process.

Going ahead to step 9:
The number 399 fits into 3870 9 times, leaving a remainder of 279.
Use 9 as the next digit of our solution. 
Result so far: 215333.9
If we subtract 3591 from 3870, we get 279.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2790, and continue the process.

Step 10:
399 goes into 2790 6 times with a remainder of 396.
Write down 6 as next digit of the result. 
Result so far: 215333.96
Subtract 2394 from 2790 to get 396.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3960, and continue the process.

Moving on to step 11:
3960 divided by 399 is 9 with a remainder of 369.
The number 9 becomes the next digit in our result. 
Result so far: 215333.969
If we subtract 3591 from 3960, we get 369.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3690, and continue the process.

Let's proceed to step 12:
If we divide 3690 by 399, we get 9 and a remainder of 99.
The next digit of our result is 9. 
Result so far: 215333.9699
If we subtract 3591 from 3690, we get 99.
Since there are no more digits in the dividend, we add a zero to the remainder making it 990, and continue the process.

Our division results in 215333.9699 with a remaining 0.00099.