401865 divided by 91 
The aim is to understand the frequency of 91 in 401865.

Let's proceed to step 1:
When dividing 4 by 91, we get 0 with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Fetch the next digit (0) from the dividend, attach it to 4 and continue: 40 / 91

Moving on to step 2:
91 goes into 40 0 times with a remainder of 40.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 40 after subtracting 0 from 40.
Grab the next digit (1) from the dividend, add it to 40, then carry on: 401 / 91

Step 3:
When dividing 401 by 91, we get 4 with a remainder of 37.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtracting 364 from 401 leaves us with 37.
Bring next digit (8) of the dividend behind the 37 and repeat the process: 378 / 91

Advancing to step 4:
When dividing 378 by 91, we get 4 with a remainder of 14.
Use 4 as the next digit of our solution. 
Result so far: 44.0
The remainder is 14 after subtracting 364 from 378.
Bring next digit (6) of the dividend behind the 14 and repeat the process: 146 / 91

Let's proceed to step 5:
If we divide 146 by 91, we get 1 and a remainder of 55.
Put 1 as the next digit of the answer. 
Result so far: 441.0
The remainder is 55 after subtracting 91 from 146.
Fetch the next digit (5) from the dividend, attach it to 55 and continue: 555 / 91

On to step 6:
91 goes into 555 6 times with a remainder of 9.
Write down 6 as next digit of the result. 
Result so far: 4416.0
The remainder is 9 after subtracting 546 from 555.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 7:
The number 91 fits into 90 0 times, leaving a remainder of 90.
Put 0 as the next digit of the answer. 
Result so far: 4416.0
If we subtract 0 from 90, we get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Let's proceed to step 8:
91 can be fit into 900 9 times, resulting in a remainder of 81.
The next digit of our result is 9. 
Result so far: 4416.09
If we take 819 away from 900, we end up with 81.
Since there are no more digits in the dividend, we add a zero to the remainder making it 810, and continue the process.

Going ahead to step 9:
The number 91 fits into 810 8 times, leaving a remainder of 82.
Use 8 as the next digit of our solution. 
Result so far: 4416.098
Subtracting 728 from 810 leaves us with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

On to step 10:
If we divide 820 by 91, we get 9 and a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 4416.0989
If we take 819 away from 820, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 11:
91 goes into 10 0 times with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 4416.0989
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 12:
The number 91 fits into 100 1 times, leaving a remainder of 9.
The next digit of our result is 1. 
Result so far: 4416.098901
The remainder is 9 after subtracting 91 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 13:
If we divide 90 by 91, we get 0 and a remainder of 90.
Write down 0 as next digit of the result. 
Result so far: 4416.098901
Subtract 0 from 90 to get 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Advancing to step 14:
91 goes into 900 9 times with a remainder of 81.
The number 9 becomes the next digit in our result. 
Result so far: 4416.09890109
Subtracting 819 from 900 leaves us with 81.
Since there are no more digits in the dividend, we add a zero to the remainder making it 810, and continue the process.

The final result is 4416.09890109 with a remainder of 8.1e-08.