664350 ÷ 91 
The aim is to understand the frequency of 91 in 664350.

Step 1:
6 divided by 91 is 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 91

Moving on to step 2:
91 goes into 66 0 times with a remainder of 66.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 66 leaves us with 66.
Grab the next digit (4) from the dividend, add it to 66, then carry on: 664 / 91

Moving on to step 3:
When dividing 664 by 91, we get 7 with a remainder of 27.
Put 7 as the next digit of the answer. 
Result so far: 7.0
The remainder is 27 after subtracting 637 from 664.
Append the next digit (3) from the dividend to 27 and continue with: 273 / 91

On to step 4:
If we divide 273 by 91, we get 3 and a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 73.0
Subtract 273 from 273 to get 0.
Take the next digit (5) from the dividend and append it to 0, then repeat: 5 / 91

Moving on to step 5:
91 goes into 5 0 times with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 730.0
Subtracting 0 from 5 leaves us with 5.
Grab the next digit (0) from the dividend, add it to 5, then carry on: 50 / 91

Advancing to step 6:
91 goes into 50 0 times with a remainder of 50.
Write down 0 as next digit of the result. 
Result so far: 7300.0
Subtracting 0 from 50 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

On to step 7:
The number 91 fits into 500 5 times, leaving a remainder of 45.
The next digit of our result is 5. 
Result so far: 7300.5
If we subtract 455 from 500, we get 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 8:
If we divide 450 by 91, we get 4 and a remainder of 86.
Use 4 as the next digit of our solution. 
Result so far: 7300.54
Subtracting 364 from 450 leaves us with 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

Going ahead to step 9:
91 can be fit into 860 9 times, resulting in a remainder of 41.
Put 9 as the next digit of the answer. 
Result so far: 7300.549
Subtract 819 from 860 to get 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Moving on to step 10:
410 divided by 91 is 4 with a remainder of 46.
Record the quotient 4 as the next digit in the result. 
Result so far: 7300.5494
If we subtract 364 from 410, we get 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Going ahead to step 11:
If we divide 460 by 91, we get 5 and a remainder of 5.
The next digit of our result is 5. 
Result so far: 7300.54945
Subtracting 455 from 460 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 12:
If we divide 50 by 91, we get 0 and a remainder of 50.
Use 0 as the next digit of our solution. 
Result so far: 7300.54945
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 13:
91 can be fit into 500 5 times, resulting in a remainder of 45.
The number 5 becomes the next digit in our result. 
Result so far: 7300.5494505
Subtract 455 from 500 to get 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 14:
91 can be fit into 450 4 times, resulting in a remainder of 86.
Write down 4 as next digit of the result. 
Result so far: 7300.54945054
Deduct 364 from 450 and we're left with 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

After the division, we end up with 7300.54945054 and a remainder of 8.6e-08.