Let's divide 235581 by 91
The aim is to understand the frequency of 91 in 235581.

Advancing to step 1:
91 can be fit into 2 0 times, resulting in a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Bring next digit (3) of the dividend behind the 2 and repeat the process: 23 / 91

Moving on to step 2:
When dividing 23 by 91, we get 0 with a remainder of 23.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 23 to get 23.
Append the next digit (5) from the dividend to 23 and continue with: 235 / 91

Advancing to step 3:
235 divided by 91 is 2 with a remainder of 53.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Subtract 182 from 235 to get 53.
Append the next digit (5) from the dividend to 53 and continue with: 535 / 91

Going ahead to step 4:
535 divided by 91 is 5 with a remainder of 80.
Put 5 as the next digit of the answer. 
Result so far: 25.0
Deduct 455 from 535 and we're left with 80.
Bring next digit (8) of the dividend behind the 80 and repeat the process: 808 / 91

Let's proceed to step 5:
91 can be fit into 808 8 times, resulting in a remainder of 80.
Record the quotient 8 as the next digit in the result. 
Result so far: 258.0
If we subtract 728 from 808, we get 80.
Grab the next digit (1) from the dividend, add it to 80, then carry on: 801 / 91

Let's proceed to step 6:
If we divide 801 by 91, we get 8 and a remainder of 73.
Record the quotient 8 as the next digit in the result. 
Result so far: 2588.0
Deduct 728 from 801 and we're left with 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Going ahead to step 7:
91 goes into 730 8 times with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 2588.8
If we take 728 away from 730, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 8:
When dividing 20 by 91, we get 0 with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 2588.8
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 9:
When dividing 200 by 91, we get 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 2588.802
Subtract 182 from 200 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 10:
If we divide 180 by 91, we get 1 and a remainder of 89.
Use 1 as the next digit of our solution. 
Result so far: 2588.8021
Deduct 91 from 180 and we're left with 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Advancing to step 11:
890 divided by 91 is 9 with a remainder of 71.
Put 9 as the next digit of the answer. 
Result so far: 2588.80219
Subtracting 819 from 890 leaves us with 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Let's proceed to step 12:
91 can be fit into 710 7 times, resulting in a remainder of 73.
Put 7 as the next digit of the answer. 
Result so far: 2588.802197
If we subtract 637 from 710, we get 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Moving on to step 13:
730 divided by 91 is 8 with a remainder of 2.
The next digit of our result is 8. 
Result so far: 2588.8021978
If we subtract 728 from 730, we get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 14:
The number 91 fits into 20 0 times, leaving a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 2588.8021978
If we take 0 away from 20, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Our division results in 2588.8021978 with a remaining 2e-08.