We're dividing 28172553 by 90 
The aim is to understand the frequency of 90 in 28172553.

Going ahead to step 1:
The number 90 fits into 2 0 times, leaving a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Take the next digit (8) from the dividend and append it to 2, then repeat: 28 / 90

On to step 2:
The number 90 fits into 28 0 times, leaving a remainder of 28.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 28 and we're left with 28.
Fetch the next digit (1) from the dividend, attach it to 28 and continue: 281 / 90

Let's proceed to step 3:
If we divide 281 by 90, we get 3 and a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtract 270 from 281 to get 11.
Include the next digit (7) from the dividend after 11, then repeat: 117 / 90

Moving on to step 4:
When dividing 117 by 90, we get 1 with a remainder of 27.
Write down 1 as next digit of the result. 
Result so far: 31.0
The remainder is 27 after subtracting 90 from 117.
Take the next digit (2) from the dividend and append it to 27, then repeat: 272 / 90

Advancing to step 5:
The number 90 fits into 272 3 times, leaving a remainder of 2.
Write down 3 as next digit of the result. 
Result so far: 313.0
The remainder is 2 after subtracting 270 from 272.
Grab the next digit (5) from the dividend, add it to 2, then carry on: 25 / 90

On to step 6:
90 goes into 25 0 times with a remainder of 25.
Record the quotient 0 as the next digit in the result. 
Result so far: 3130.0
Subtract 0 from 25 to get 25.
Bring next digit (5) of the dividend behind the 25 and repeat the process: 255 / 90

Let's proceed to step 7:
90 goes into 255 2 times with a remainder of 75.
Record the quotient 2 as the next digit in the result. 
Result so far: 31302.0
If we take 180 away from 255, we end up with 75.
Append the next digit (3) from the dividend to 75 and continue with: 753 / 90

Let's proceed to step 8:
The number 90 fits into 753 8 times, leaving a remainder of 33.
Use 8 as the next digit of our solution. 
Result so far: 313028.0
Deduct 720 from 753 and we're left 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.

Moving on to step 9:
330 divided by 90 is 3 with a remainder of 60.
Write down 3 as next digit of the result. 
Result so far: 313028.3
Deduct 270 from 330 and we're left with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

On to step 10:
600 divided by 90 is 6 with a remainder of 60.
Record the quotient 6 as the next digit in the result. 
Result so far: 313028.36
Deduct 540 from 600 and we're left with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Moving on to step 11:
90 goes into 600 6 times with a remainder of 60.
Record the quotient 6 as the next digit in the result. 
Result so far: 313028.366
The remainder is 60 after subtracting 540 from 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

The final result is 313028.366 with a remainder of 0.006.