257996 divided by 91 
The aim is to understand the frequency of 91 in 257996.

On to step 1:
When dividing 2 by 91, we get 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 91

Moving on to step 2:
91 can be fit into 25 0 times, resulting in a remainder of 25.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 25 to get 25.
Take the next digit (7) from the dividend and append it to 25, then repeat: 257 / 91

On to step 3:
257 divided by 91 is 2 with a remainder of 75.
The next digit of our result is 2. 
Result so far: 2.0
Subtracting 182 from 257 leaves us with 75.
Append the next digit (9) from the dividend to 75 and continue with: 759 / 91

On to step 4:
When dividing 759 by 91, we get 8 with a remainder of 31.
The number 8 becomes the next digit in our result. 
Result so far: 28.0
Subtract 728 from 759 to get 31.
Include the next digit (9) from the dividend after 31, then repeat: 319 / 91

On to step 5:
If we divide 319 by 91, we get 3 and a remainder of 46.
Put 3 as the next digit of the answer. 
Result so far: 283.0
Subtract 273 from 319 to get 46.
Fetch the next digit (6) from the dividend, attach it to 46 and continue: 466 / 91

Advancing to step 6:
If we divide 466 by 91, we get 5 and a remainder of 11.
The number 5 becomes the next digit in our result. 
Result so far: 2835.0
If we take 455 away from 466, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 7:
When dividing 110 by 91, we get 1 with a remainder of 19.
The next digit of our result is 1. 
Result so far: 2835.1
If we subtract 91 from 110, we get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Going ahead to step 8:
190 divided by 91 is 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 2835.12
Deduct 182 from 190 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 9:
91 can be fit into 80 0 times, resulting in a remainder of 80.
The number 0 becomes the next digit in our result. 
Result so far: 2835.12
Deduct 0 from 80 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Advancing to step 10:
When dividing 800 by 91, we get 8 with a remainder of 72.
The number 8 becomes the next digit in our result. 
Result so far: 2835.1208
Deduct 728 from 800 and we're left with 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Advancing to step 11:
The number 91 fits into 720 7 times, leaving a remainder of 83.
Record the quotient 7 as the next digit in the result. 
Result so far: 2835.12087
Subtract 637 from 720 to get 83.
Since there are no more digits in the dividend, we add a zero to the remainder making it 830, and continue the process.

On to step 12:
The number 91 fits into 830 9 times, leaving a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 2835.120879
Subtract 819 from 830 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 13:
When dividing 110 by 91, we get 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 2835.1208791
Subtracting 91 from 110 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 14:
If we divide 190 by 91, we get 2 and a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 2835.12087912
Deduct 182 from 190 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The final outcome is 2835.12087912, with a leftover of 8e-09.