We look at the division of 185815 by 90 
The aim is to understand the frequency of 90 in 185815.

Going ahead to step 1:
If we divide 1 by 90, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Include the next digit (8) from the dividend after 1, then repeat: 18 / 90

Going ahead to step 2:
The number 90 fits into 18 0 times, leaving a remainder of 18.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 18, we get 18.
Grab the next digit (5) from the dividend, add it to 18, then carry on: 185 / 90

Going ahead to step 3:
90 can be fit into 185 2 times, resulting in a remainder of 5.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
Subtract 180 from 185 to get 5.
Grab the next digit (8) from the dividend, add it to 5, then carry on: 58 / 90

Going ahead to step 4:
When dividing 58 by 90, we get 0 with a remainder of 58.
Write down 0 as next digit of the result. 
Result so far: 20.0
Subtract 0 from 58 to get 58.
Include the next digit (1) from the dividend after 58, then repeat: 581 / 90

Let's proceed to step 5:
The number 90 fits into 581 6 times, leaving a remainder of 41.
The number 6 becomes the next digit in our result. 
Result so far: 206.0
Deduct 540 from 581 and we're left with 41.
Include the next digit (5) from the dividend after 41, then repeat: 415 / 90

Going ahead to step 6:
If we divide 415 by 90, we get 4 and a remainder of 55.
Use 4 as the next digit of our solution. 
Result so far: 2064.0
Subtracting 360 from 415 leaves us with 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Going ahead to step 7:
If we divide 550 by 90, we get 6 and a remainder of 10.
The next digit of our result is 6. 
Result so far: 2064.6
If we take 540 away from 550, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 8:
90 can be fit into 100 1 times, resulting in a remainder of 10.
Write down 1 as next digit of the result. 
Result so far: 2064.61
Subtracting 90 from 100 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 9:
90 can be fit into 100 1 times, resulting in a remainder of 10.
Put 1 as the next digit of the answer. 
Result so far: 2064.611
Subtract 90 from 100 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Our division results in 2064.611 with a remaining 0.001.