We look at the division of 17925575 by 321 
The aim is to understand the frequency of 321 in 17925575.

On to step 1:
321 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Include the next digit (7) from the dividend after 1, then repeat: 17 / 321

Step 2:
The number 321 fits into 17 0 times, leaving a remainder of 17.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 17, we get 17.
Take the next digit (9) from the dividend and append it to 17, then repeat: 179 / 321

Let's proceed to step 3:
179 divided by 321 is 0 with a remainder of 179.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 179, we end up with 179.
Append the next digit (2) from the dividend to 179 and continue with: 1792 / 321

On to step 4:
When dividing 1792 by 321, we get 5 with a remainder of 187.
The next digit of our result is 5. 
Result so far: 5.0
Subtract 1605 from 1792 to get 187.
Take the next digit (5) from the dividend and append it to 187, then repeat: 1875 / 321

Step 5:
When dividing 1875 by 321, we get 5 with a remainder of 270.
Record the quotient 5 as the next digit in the result. 
Result so far: 55.0
If we subtract 1605 from 1875, we get 270.
Grab the next digit (5) from the dividend, add it to 270, then carry on: 2705 / 321

Step 6:
When dividing 2705 by 321, we get 8 with a remainder of 137.
Write down 8 as next digit of the result. 
Result so far: 558.0
Subtracting 2568 from 2705 leaves us with 137.
Include the next digit (7) from the dividend after 137, then repeat: 1377 / 321

Advancing to step 7:
When dividing 1377 by 321, we get 4 with a remainder of 93.
The number 4 becomes the next digit in our result. 
Result so far: 5584.0
If we subtract 1284 from 1377, we get 93.
Bring next digit (5) of the dividend behind the 93 and repeat the process: 935 / 321

Advancing to step 8:
When dividing 935 by 321, we get 2 with a remainder of 293.
Write down 2 as next digit of the result. 
Result so far: 55842.0
The remainder is 293 after subtracting 642 from 935.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2930, and continue the process.

Let's proceed to step 9:
When dividing 2930 by 321, we get 9 with a remainder of 41.
Put 9 as the next digit of the answer. 
Result so far: 55842.9
Deduct 2889 from 2930 and we're left with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Let's proceed to step 10:
410 divided by 321 is 1 with a remainder of 89.
Put 1 as the next digit of the answer. 
Result so far: 55842.91
Subtracting 321 from 410 leaves us with 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Moving on to step 11:
890 divided by 321 is 2 with a remainder of 248.
Put 2 as the next digit of the answer. 
Result so far: 55842.912
If we subtract 642 from 890, we get 248.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2480, and continue the process.

Let's proceed to step 12:
321 can be fit into 2480 7 times, resulting in a remainder of 233.
The next digit of our result is 7. 
Result so far: 55842.9127
The remainder is 233 after subtracting 2247 from 2480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2330, and continue the process.

Advancing to step 13:
321 can be fit into 2330 7 times, resulting in a remainder of 83.
Use 7 as the next digit of our solution. 
Result so far: 55842.91277
If we subtract 2247 from 2330, we get 83.
Since there are no more digits in the dividend, we add a zero to the remainder making it 830, and continue the process.

After the division, we end up with 55842.91277 and a remainder of 8.3e-05.