Let's divide 636591 by 91
The aim is to understand the frequency of 91 in 636591.

Going ahead to step 1:
6 divided by 91 is 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (3) from the dividend after 6, then repeat: 63 / 91

On to step 2:
91 can be fit into 63 0 times, resulting in a remainder of 63.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 63, we end up with 63.
Fetch the next digit (6) from the dividend, attach it to 63 and continue: 636 / 91

Let's proceed to step 3:
91 goes into 636 6 times with a remainder of 90.
The number 6 becomes the next digit in our result. 
Result so far: 6.0
If we take 546 away from 636, we end up with 90.
Grab the next digit (5) from the dividend, add it to 90, then carry on: 905 / 91

Moving on to step 4:
The number 91 fits into 905 9 times, leaving a remainder of 86.
Record the quotient 9 as the next digit in the result. 
Result so far: 69.0
If we subtract 819 from 905, we get 86.
Grab the next digit (9) from the dividend, add it to 86, then carry on: 869 / 91

Advancing to step 5:
If we divide 869 by 91, we get 9 and a remainder of 50.
The number 9 becomes the next digit in our result. 
Result so far: 699.0
If we take 819 away from 869, we end up with 50.
Bring next digit (1) of the dividend behind the 50 and repeat the process: 501 / 91

On to step 6:
When dividing 501 by 91, we get 5 with a remainder of 46.
Write down 5 as next digit of the result. 
Result so far: 6995.0
The remainder is 46 after subtracting 455 from 501.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Advancing to step 7:
If we divide 460 by 91, we get 5 and a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 6995.5
Subtract 455 from 460 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 8:
If we divide 50 by 91, we get 0 and a remainder of 50.
Put 0 as the next digit of the answer. 
Result so far: 6995.5
The remainder is 50 after subtracting 0 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 9:
When dividing 500 by 91, we get 5 with a remainder of 45.
Record the quotient 5 as the next digit in the result. 
Result so far: 6995.505
Subtract 455 from 500 to get 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 10:
91 can be fit into 450 4 times, resulting in a remainder of 86.
Put 4 as the next digit of the answer. 
Result so far: 6995.5054
Subtract 364 from 450 to get 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

Moving on to step 11:
If we divide 860 by 91, we get 9 and a remainder of 41.
Write down 9 as next digit of the result. 
Result so far: 6995.50549
Deduct 819 from 860 and we're left with 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Going ahead to step 12:
91 goes into 410 4 times with a remainder of 46.
The next digit of our result is 4. 
Result so far: 6995.505494
Subtracting 364 from 410 leaves us with 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Going ahead to step 13:
If we divide 460 by 91, we get 5 and a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 6995.5054945
If we take 455 away from 460, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 14:
If we divide 50 by 91, we get 0 and a remainder of 50.
Put 0 as the next digit of the answer. 
Result so far: 6995.5054945
If we subtract 0 from 50, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Our division results in 6995.5054945 with a remaining 5e-08.