91246025 ÷ 321 
The aim is to understand the frequency of 321 in 91246025.

Advancing to step 1:
The number 321 fits into 9 0 times, leaving a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Bring next digit (1) of the dividend behind the 9 and repeat the process: 91 / 321

Advancing to step 2:
The number 321 fits into 91 0 times, leaving a remainder of 91.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 91 to get 91.
Bring next digit (2) of the dividend behind the 91 and repeat the process: 912 / 321

Advancing to step 3:
If we divide 912 by 321, we get 2 and a remainder of 270.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtract 642 from 912 to get 270.
Fetch the next digit (4) from the dividend, attach it to 270 and continue: 2704 / 321

Let's proceed to step 4:
The number 321 fits into 2704 8 times, leaving a remainder of 136.
The next digit of our result is 8. 
Result so far: 28.0
Deduct 2568 from 2704 and we're left with 136.
Include the next digit (6) from the dividend after 136, then repeat: 1366 / 321

Let's proceed to step 5:
1366 divided by 321 is 4 with a remainder of 82.
Write down 4 as next digit of the result. 
Result so far: 284.0
The remainder is 82 after subtracting 1284 from 1366.
Grab the next digit (0) from the dividend, add it to 82, then carry on: 820 / 321

Advancing to step 6:
The number 321 fits into 820 2 times, leaving a remainder of 178.
The next digit of our result is 2. 
Result so far: 2842.0
Deduct 642 from 820 and we're left with 178.
Fetch the next digit (2) from the dividend, attach it to 178 and continue: 1782 / 321

On to step 7:
321 goes into 1782 5 times with a remainder of 177.
Use 5 as the next digit of our solution. 
Result so far: 28425.0
If we take 1605 away from 1782, we end up with 177.
Append the next digit (5) from the dividend to 177 and continue with: 1775 / 321

Step 8:
321 goes into 1775 5 times with a remainder of 170.
Use 5 as the next digit of our solution. 
Result so far: 284255.0
If we take 1605 away from 1775, we end up with 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1700, and continue the process.

Let's proceed to step 9:
The number 321 fits into 1700 5 times, leaving a remainder of 95.
The next digit of our result is 5. 
Result so far: 284255.5
Subtracting 1605 from 1700 leaves us with 95.
Since there are no more digits in the dividend, we add a zero to the remainder making it 950, and continue the process.

Advancing to step 10:
The number 321 fits into 950 2 times, leaving a remainder of 308.
Put 2 as the next digit of the answer. 
Result so far: 284255.52
If we take 642 away from 950, we end up with 308.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3080, and continue the process.

On to step 11:
If we divide 3080 by 321, we get 9 and a remainder of 191.
Write down 9 as next digit of the result. 
Result so far: 284255.529
If we subtract 2889 from 3080, we get 191.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1910, and continue the process.

On to step 12:
321 goes into 1910 5 times with a remainder of 305.
The next digit of our result is 5. 
Result so far: 284255.5295
Subtract 1605 from 1910 to get 305.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3050, and continue the process.

Advancing to step 13:
If we divide 3050 by 321, we get 9 and a remainder of 161.
Write down 9 as next digit of the result. 
Result so far: 284255.52959
If we subtract 2889 from 3050, we get 161.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1610, and continue the process.

On to step 14:
321 goes into 1610 5 times with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 284255.529595
The remainder is 5 after subtracting 1605 from 1610.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 15:
The number 321 fits into 50 0 times, leaving a remainder of 50.
Put 0 as the next digit of the answer. 
Result so far: 284255.529595
If we subtract 0 from 50, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 16:
321 can be fit into 500 1 times, resulting in a remainder of 179.
The number 1 becomes the next digit in our result. 
Result so far: 284255.52959501
Subtract 321 from 500 to get 179.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1790, and continue the process.

The quotient of the division is 284255.52959501, and the remainder is 1.79e-07.