We look at the division of 557862 by 90 
The aim is to understand the frequency of 90 in 557862.

Advancing to step 1:
The number 90 fits into 5 0 times, leaving a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Append the next digit (5) from the dividend to 5 and continue with: 55 / 90

Going ahead to step 2:
The number 90 fits into 55 0 times, leaving a remainder of 55.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 55, we get 55.
Append the next digit (7) from the dividend to 55 and continue with: 557 / 90

Let's proceed to step 3:
If we divide 557 by 90, we get 6 and a remainder of 17.
Record the quotient 6 as the next digit in the result. 
Result so far: 6.0
Subtract 540 from 557 to get 17.
Take the next digit (8) from the dividend and append it to 17, then repeat: 178 / 90

Let's proceed to step 4:
The number 90 fits into 178 1 times, leaving a remainder of 88.
Put 1 as the next digit of the answer. 
Result so far: 61.0
If we take 90 away from 178, we end up with 88.
Include the next digit (6) from the dividend after 88, then repeat: 886 / 90

Moving on to step 5:
The number 90 fits into 886 9 times, leaving a remainder of 76.
The number 9 becomes the next digit in our result. 
Result so far: 619.0
Subtracting 810 from 886 leaves us with 76.
Include the next digit (2) from the dividend after 76, then repeat: 762 / 90

Moving on to step 6:
If we divide 762 by 90, we get 8 and a remainder of 42.
Use 8 as the next digit of our solution. 
Result so far: 6198.0
If we take 720 away from 762, we end up with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Advancing to step 7:
If we divide 420 by 90, we get 4 and a remainder of 60.
The next digit of our result is 4. 
Result so far: 6198.4
Subtract 360 from 420 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 8:
600 divided by 90 is 6 with a remainder of 60.
Write down 6 as next digit of the result. 
Result so far: 6198.46
Subtract 540 from 600 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Advancing to step 9:
600 divided by 90 is 6 with a remainder of 60.
The number 6 becomes the next digit in our result. 
Result so far: 6198.466
If we take 540 away from 600, we end up 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.

The final result is 6198.466 with a remainder of 0.006.