665045 ÷ 91 
The aim is to understand the frequency of 91 in 665045.

Step 1:
When dividing 6 by 91, we get 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 91

Advancing to step 2:
91 goes into 66 0 times with a remainder of 66.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 66 leaves us with 66.
Grab the next digit (5) from the dividend, add it to 66, then carry on: 665 / 91

Going ahead to step 3:
The number 91 fits into 665 7 times, leaving a remainder of 28.
Write down 7 as next digit of the result. 
Result so far: 7.0
Subtracting 637 from 665 leaves us with 28.
Take the next digit (0) from the dividend and append it to 28, then repeat: 280 / 91

Advancing to step 4:
91 can be fit into 280 3 times, resulting in a remainder of 7.
The next digit of our result is 3. 
Result so far: 73.0
Subtracting 273 from 280 leaves us with 7.
Bring next digit (4) of the dividend behind the 7 and repeat the process: 74 / 91

Let's proceed to step 5:
91 can be fit into 74 0 times, resulting in a remainder of 74.
The number 0 becomes the next digit in our result. 
Result so far: 730.0
Deduct 0 from 74 and we're left with 74.
Include the next digit (5) from the dividend after 74, then repeat: 745 / 91

Going ahead to step 6:
The number 91 fits into 745 8 times, leaving a remainder of 17.
Record the quotient 8 as the next digit in the result. 
Result so far: 7308.0
Subtracting 728 from 745 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 7:
91 can be fit into 170 1 times, resulting in a remainder of 79.
Use 1 as the next digit of our solution. 
Result so far: 7308.1
Subtract 91 from 170 to get 79.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Moving on to step 8:
When dividing 790 by 91, we get 8 with a remainder of 62.
The next digit of our result is 8. 
Result so far: 7308.18
Deduct 728 from 790 and we're left with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Step 9:
91 goes into 620 6 times with a remainder of 74.
Put 6 as the next digit of the answer. 
Result so far: 7308.186
Subtracting 546 from 620 leaves us with 74.
Since there are no more digits in the dividend, we add a zero to the remainder making it 740, and continue the process.

On to step 10:
91 goes into 740 8 times with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 7308.1868
If we take 728 away from 740, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 11:
91 can be fit into 120 1 times, resulting in a remainder of 29.
Use 1 as the next digit of our solution. 
Result so far: 7308.18681
Subtracting 91 from 120 leaves us with 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Advancing to step 12:
91 can be fit into 290 3 times, resulting in a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 7308.186813
Deduct 273 from 290 and we're left with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 13:
91 can be fit into 170 1 times, resulting in a remainder of 79.
The next digit of our result is 1. 
Result so far: 7308.1868131
The remainder is 79 after subtracting 91 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 790, and continue the process.

Step 14:
91 goes into 790 8 times with a remainder of 62.
Use 8 as the next digit of our solution. 
Result so far: 7308.18681318
If we subtract 728 from 790, we get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

The final result is 7308.18681318 with a remainder of 6.2e-08.