235191 ÷ 90 
The aim is to understand the frequency of 90 in 235191.

Advancing to step 1:
90 goes into 2 0 times with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Append the next digit (3) from the dividend to 2 and continue with: 23 / 90

Going ahead to step 2:
90 can be fit into 23 0 times, resulting in a remainder of 23.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 23 to get 23.
Fetch the next digit (5) from the dividend, attach it to 23 and continue: 235 / 90

Advancing to step 3:
The number 90 fits into 235 2 times, leaving a remainder of 55.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we take 180 away from 235, we end up with 55.
Append the next digit (1) from the dividend to 55 and continue with: 551 / 90

Let's proceed to step 4:
551 divided by 90 is 6 with a remainder of 11.
Record the quotient 6 as the next digit in the result. 
Result so far: 26.0
Deduct 540 from 551 and we're left with 11.
Include the next digit (9) from the dividend after 11, then repeat: 119 / 90

Moving on to step 5:
If we divide 119 by 90, we get 1 and a remainder of 29.
Use 1 as the next digit of our solution. 
Result so far: 261.0
If we subtract 90 from 119, we get 29.
Include the next digit (1) from the dividend after 29, then repeat: 291 / 90

Moving on to step 6:
90 goes into 291 3 times with a remainder of 21.
The number 3 becomes the next digit in our result. 
Result so far: 2613.0
Subtract 270 from 291 to get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Let's proceed to step 7:
When dividing 210 by 90, we get 2 with a remainder of 30.
The next digit of our result is 2. 
Result so far: 2613.2
If we subtract 180 from 210, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 8:
90 can be fit into 300 3 times, resulting in a remainder of 30.
Put 3 as the next digit of the answer. 
Result so far: 2613.23
If we subtract 270 from 300, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 9:
300 divided by 90 is 3 with a remainder of 30.
The next digit of our result is 3. 
Result so far: 2613.233
Subtract 270 from 300 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

The final result is 2613.233 with a remainder of 0.003.