We look at the division of 255830 by 90 
The aim is to understand the frequency of 90 in 255830.

Step 1:
90 goes into 2 0 times with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Include the next digit (5) from the dividend after 2, then repeat: 25 / 90

Advancing to step 2:
The number 90 fits into 25 0 times, leaving a remainder of 25.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 25 to get 25.
Take the next digit (5) from the dividend and append it to 25, then repeat: 255 / 90

Step 3:
255 divided by 90 is 2 with a remainder of 75.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Subtract 180 from 255 to get 75.
Grab the next digit (8) from the dividend, add it to 75, then carry on: 758 / 90

Going ahead to step 4:
If we divide 758 by 90, we get 8 and a remainder of 38.
Use 8 as the next digit of our solution. 
Result so far: 28.0
If we subtract 720 from 758, we get 38.
Include the next digit (3) from the dividend after 38, then repeat: 383 / 90

Moving on to step 5:
383 divided by 90 is 4 with a remainder of 23.
Use 4 as the next digit of our solution. 
Result so far: 284.0
Subtract 360 from 383 to get 23.
Include the next digit (0) from the dividend after 23, then repeat: 230 / 90

Let's proceed to step 6:
If we divide 230 by 90, we get 2 and a remainder of 50.
The next digit of our result is 2. 
Result so far: 2842.0
If we subtract 180 from 230, 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.

Moving on to step 7:
If we divide 500 by 90, we get 5 and a remainder of 50.
Use 5 as the next digit of our solution. 
Result so far: 2842.5
Subtract 450 from 500 to 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.

Let's proceed to step 8:
When dividing 500 by 90, we get 5 with a remainder of 50.
Record the quotient 5 as the next digit in the result. 
Result so far: 2842.55
Subtract 450 from 500 to 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.

After the division, we end up with 2842.55 and a remainder of 0.05.