We're dividing 915919 by 91 
The aim is to understand the frequency of 91 in 915919.

Advancing to step 1:
The number 91 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.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 91

Let's proceed to step 2:
The number 91 fits into 91 1 times, leaving a remainder of 0.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 91 from 91 and we're left with 0.
Grab the next digit (5) from the dividend, add it to 0, then carry on: 5 / 91

On to step 3:
If we divide 5 by 91, we get 0 and a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Subtract 0 from 5 to get 5.
Bring next digit (9) of the dividend behind the 5 and repeat the process: 59 / 91

Step 4:
59 divided by 91 is 0 with a remainder of 59.
Use 0 as the next digit of our solution. 
Result so far: 100.0
Deduct 0 from 59 and we're left with 59.
Bring next digit (1) of the dividend behind the 59 and repeat the process: 591 / 91

On to step 5:
The number 91 fits into 591 6 times, leaving a remainder of 45.
Record the quotient 6 as the next digit in the result. 
Result so far: 1006.0
Subtract 546 from 591 to get 45.
Fetch the next digit (9) from the dividend, attach it to 45 and continue: 459 / 91

Step 6:
The number 91 fits into 459 5 times, leaving a remainder of 4.
The number 5 becomes the next digit in our result. 
Result so far: 10065.0
If we take 455 away from 459, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 7:
91 goes into 40 0 times with a remainder of 40.
Record the quotient 0 as the next digit in the result. 
Result so far: 10065.0
If we take 0 away from 40, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 8:
400 divided by 91 is 4 with a remainder of 36.
Use 4 as the next digit of our solution. 
Result so far: 10065.04
Subtracting 364 from 400 leaves us with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Let's proceed to step 9:
The number 91 fits into 360 3 times, leaving a remainder of 87.
The next digit of our result is 3. 
Result so far: 10065.043
If we take 273 away from 360, we end up with 87.
Since there are no more digits in the dividend, we add a zero to the remainder making it 870, and continue the process.

Let's proceed to step 10:
91 goes into 870 9 times with a remainder of 51.
The number 9 becomes the next digit in our result. 
Result so far: 10065.0439
If we subtract 819 from 870, we get 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Step 11:
91 goes into 510 5 times with a remainder of 55.
The number 5 becomes the next digit in our result. 
Result so far: 10065.04395
The remainder is 55 after subtracting 455 from 510.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Going ahead to step 12:
If we divide 550 by 91, we get 6 and a remainder of 4.
The next digit of our result is 6. 
Result so far: 10065.043956
Deduct 546 from 550 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 13:
The number 91 fits into 40 0 times, leaving a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 10065.043956
Deduct 0 from 40 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 14:
91 can be fit into 400 4 times, resulting in a remainder of 36.
Put 4 as the next digit of the answer. 
Result so far: 10065.04395604
If we take 364 away from 400, we end up with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

The final outcome is 10065.04395604, with a leftover of 3.6e-08.