891867 divided by 91 
The aim is to understand the frequency of 91 in 891867.

Moving on to step 1:
91 can be fit into 8 0 times, resulting in a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Append the next digit (9) from the dividend to 8 and continue with: 89 / 91

On to step 2:
91 goes into 89 0 times with a remainder of 89.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 89 after subtracting 0 from 89.
Include the next digit (1) from the dividend after 89, then repeat: 891 / 91

Step 3:
91 can be fit into 891 9 times, resulting in a remainder of 72.
Write down 9 as next digit of the result. 
Result so far: 9.0
If we take 819 away from 891, we end up with 72.
Bring next digit (8) of the dividend behind the 72 and repeat the process: 728 / 91

Step 4:
When dividing 728 by 91, we get 8 with a remainder of 0.
The number 8 becomes the next digit in our result. 
Result so far: 98.0
If we subtract 728 from 728, we get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 91

Moving on to step 5:
91 goes into 6 0 times with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 980.0
Deduct 0 from 6 and we're left with 6.
Bring next digit (7) of the dividend behind the 6 and repeat the process: 67 / 91

Let's proceed to step 6:
If we divide 67 by 91, we get 0 and a remainder of 67.
Record the quotient 0 as the next digit in the result. 
Result so far: 9800.0
If we subtract 0 from 67, we get 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 7:
If we divide 670 by 91, we get 7 and a remainder of 33.
The number 7 becomes the next digit in our result. 
Result so far: 9800.7
The remainder is 33 after subtracting 637 from 670.
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 8:
91 can be fit into 330 3 times, resulting in a remainder of 57.
Put 3 as the next digit of the answer. 
Result so far: 9800.73
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.

Moving on to step 9:
91 can be fit into 570 6 times, resulting in a remainder of 24.
Write down 6 as next digit of the result. 
Result so far: 9800.736
If we take 546 away from 570, we end up 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.

Advancing to step 10:
When dividing 240 by 91, we get 2 with a remainder of 58.
Write down 2 as next digit of the result. 
Result so far: 9800.7362
Subtract 182 from 240 to get 58.
Since there are no more digits in the dividend, we add a zero to the remainder making it 580, and continue the process.

Going ahead to step 11:
91 can be fit into 580 6 times, resulting in a remainder of 34.
Record the quotient 6 as the next digit in the result. 
Result so far: 9800.73626
If we take 546 away from 580, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Going ahead to step 12:
91 can be fit into 340 3 times, resulting in a remainder of 67.
Record the quotient 3 as the next digit in the result. 
Result so far: 9800.736263
If we take 273 away from 340, we end up 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.

On to step 13:
91 goes into 670 7 times with a remainder of 33.
Put 7 as the next digit of the answer. 
Result so far: 9800.7362637
If we take 637 away from 670, we end up 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.

Advancing to step 14:
If we divide 330 by 91, we get 3 and a remainder of 57.
Use 3 as the next digit of our solution. 
Result so far: 9800.73626373
The remainder is 57 after subtracting 273 from 330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

The final outcome is 9800.73626373, with a leftover of 5.7e-08.