We're dividing 478958 by 91 
The aim is to understand the frequency of 91 in 478958.

Going ahead to step 1:
If we divide 4 by 91, we get 0 and a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Include the next digit (7) from the dividend after 4, then repeat: 47 / 91

Advancing to step 2:
When dividing 47 by 91, we get 0 with a remainder of 47.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 47, we get 47.
Grab the next digit (8) from the dividend, add it to 47, then carry on: 478 / 91

Moving on to step 3:
If we divide 478 by 91, we get 5 and a remainder of 23.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
If we take 455 away from 478, we end up with 23.
Bring next digit (9) of the dividend behind the 23 and repeat the process: 239 / 91

Going ahead to step 4:
If we divide 239 by 91, we get 2 and a remainder of 57.
Use 2 as the next digit of our solution. 
Result so far: 52.0
Subtract 182 from 239 to get 57.
Fetch the next digit (5) from the dividend, attach it to 57 and continue: 575 / 91

Step 5:
If we divide 575 by 91, we get 6 and a remainder of 29.
The number 6 becomes the next digit in our result. 
Result so far: 526.0
Subtract 546 from 575 to get 29.
Append the next digit (8) from the dividend to 29 and continue with: 298 / 91

On to step 6:
91 goes into 298 3 times with a remainder of 25.
Record the quotient 3 as the next digit in the result. 
Result so far: 5263.0
If we subtract 273 from 298, we get 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Let's proceed to step 7:
250 divided by 91 is 2 with a remainder of 68.
Use 2 as the next digit of our solution. 
Result so far: 5263.2
If we take 182 away from 250, we end up with 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Advancing to step 8:
91 goes into 680 7 times with a remainder of 43.
The next digit of our result is 7. 
Result so far: 5263.27
If we take 637 away from 680, we end up with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Step 9:
The number 91 fits into 430 4 times, leaving a remainder of 66.
Put 4 as the next digit of the answer. 
Result so far: 5263.274
Subtract 364 from 430 to get 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

On to step 10:
660 divided by 91 is 7 with a remainder of 23.
The number 7 becomes the next digit in our result. 
Result so far: 5263.2747
The remainder is 23 after subtracting 637 from 660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

On to step 11:
230 divided by 91 is 2 with a remainder of 48.
The next digit of our result is 2. 
Result so far: 5263.27472
The remainder is 48 after subtracting 182 from 230.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Let's proceed to step 12:
The number 91 fits into 480 5 times, leaving a remainder of 25.
The next digit of our result is 5. 
Result so far: 5263.274725
Subtracting 455 from 480 leaves us with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

Advancing to step 13:
250 divided by 91 is 2 with a remainder of 68.
Write down 2 as next digit of the result. 
Result so far: 5263.2747252
Subtracting 182 from 250 leaves us with 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Advancing to step 14:
91 can be fit into 680 7 times, resulting in a remainder of 43.
Use 7 as the next digit of our solution. 
Result so far: 5263.27472527
If we take 637 away from 680, we end up with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

The final outcome is 5263.27472527, with a leftover of 4.3e-08.