We divide 391597 by 91
The aim is to understand the frequency of 91 in 391597.

Advancing to step 1:
91 goes into 3 0 times with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 91

Step 2:
The number 91 fits into 39 0 times, leaving a remainder of 39.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 39 after subtracting 0 from 39.
Bring next digit (1) of the dividend behind the 39 and repeat the process: 391 / 91

Going ahead to step 3:
91 goes into 391 4 times with a remainder of 27.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we take 364 away from 391, we end up with 27.
Include the next digit (5) from the dividend after 27, then repeat: 275 / 91

Going ahead to step 4:
The number 91 fits into 275 3 times, leaving a remainder of 2.
Write down 3 as next digit of the result. 
Result so far: 43.0
If we subtract 273 from 275, we get 2.
Include the next digit (9) from the dividend after 2, then repeat: 29 / 91

Going ahead to step 5:
When dividing 29 by 91, we get 0 with a remainder of 29.
Put 0 as the next digit of the answer. 
Result so far: 430.0
The remainder is 29 after subtracting 0 from 29.
Include the next digit (7) from the dividend after 29, then repeat: 297 / 91

Step 6:
The number 91 fits into 297 3 times, leaving a remainder of 24.
The number 3 becomes the next digit in our result. 
Result so far: 4303.0
Deduct 273 from 297 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

On to step 7:
If we divide 240 by 91, we get 2 and a remainder of 58.
The number 2 becomes the next digit in our result. 
Result so far: 4303.2
Subtracting 182 from 240 leaves us with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Let's proceed to step 8:
580 divided by 91 is 6 with a remainder of 34.
The number 6 becomes the next digit in our result. 
Result so far: 4303.26
The remainder is 34 after subtracting 546 from 580.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Let's proceed to step 9:
91 goes into 340 3 times with a remainder of 67.
Use 3 as the next digit of our solution. 
Result so far: 4303.263
Subtracting 273 from 340 leaves us with 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

Let's proceed to step 10:
91 goes into 670 7 times with a remainder of 33.
Use 7 as the next digit of our solution. 
Result so far: 4303.2637
Deduct 637 from 670 and we're left with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

On to step 11:
The number 91 fits into 330 3 times, leaving a remainder of 57.
The number 3 becomes the next digit in our result. 
Result so far: 4303.26373
If we subtract 273 from 330, we get 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

Step 12:
When dividing 570 by 91, we get 6 with a remainder of 24.
Write down 6 as next digit of the result. 
Result so far: 4303.263736
Deduct 546 from 570 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

On to step 13:
When dividing 240 by 91, we get 2 with a remainder of 58.
Use 2 as the next digit of our solution. 
Result so far: 4303.2637362
Deduct 182 from 240 and we're left with 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Moving on to step 14:
91 goes into 580 6 times with a remainder of 34.
Use 6 as the next digit of our solution. 
Result so far: 4303.26373626
Subtract 546 from 580 to get 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

After the division, we end up with 4303.26373626 and a remainder of 3.4e-08.