We look at the division of 398319 by 75 
The aim is to understand the frequency of 75 in 398319.

Advancing to step 1:
The number 75 fits into 3 0 times, leaving a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 75

Step 2:
The number 75 fits into 39 0 times, leaving a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 39 after subtracting 0 from 39.
Append the next digit (8) from the dividend to 39 and continue with: 398 / 75

Moving on to step 3:
The number 75 fits into 398 5 times, leaving a remainder of 23.
Write down 5 as next digit of the result. 
Result so far: 5.0
Subtracting 375 from 398 leaves us with 23.
Include the next digit (3) from the dividend after 23, then repeat: 233 / 75

On to step 4:
75 goes into 233 3 times with a remainder of 8.
The next digit of our result is 3. 
Result so far: 53.0
Subtracting 225 from 233 leaves us with 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 75

Step 5:
75 goes into 81 1 times with a remainder of 6.
The next digit of our result is 1. 
Result so far: 531.0
The remainder is 6 after subtracting 75 from 81.
Include the next digit (9) from the dividend after 6, then repeat: 69 / 75

Advancing to step 6:
If we divide 69 by 75, we get 0 and a remainder of 69.
Record the quotient 0 as the next digit in the result. 
Result so far: 5310.0
If we subtract 0 from 69, we get 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Going ahead to step 7:
75 can be fit into 690 9 times, resulting in a remainder of 15.
Write down 9 as next digit of the result. 
Result so far: 5310.9
The remainder is 15 after subtracting 675 from 690.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 8:
75 goes into 150 2 times with a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 5310.92
Deduct 150 from 150 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 9:
75 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 5310.92
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 10:
The number 75 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 5310.92
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 5310.92 with a remainder of 0.0.