We look at the division of 523117 by 90 
The aim is to understand the frequency of 90 in 523117.

Going ahead to step 1:
When dividing 5 by 90, we get 0 with a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Include the next digit (2) from the dividend after 5, then repeat: 52 / 90

Advancing to step 2:
90 goes into 52 0 times with a remainder of 52.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 52, we get 52.
Fetch the next digit (3) from the dividend, attach it to 52 and continue: 523 / 90

Step 3:
90 goes into 523 5 times with a remainder of 73.
The next digit of our result is 5. 
Result so far: 5.0
Subtracting 450 from 523 leaves us with 73.
Fetch the next digit (1) from the dividend, attach it to 73 and continue: 731 / 90

Moving on to step 4:
If we divide 731 by 90, we get 8 and a remainder of 11.
Record the quotient 8 as the next digit in the result. 
Result so far: 58.0
Deduct 720 from 731 and we're left with 11.
Fetch the next digit (1) from the dividend, attach it to 11 and continue: 111 / 90

Advancing to step 5:
90 goes into 111 1 times with a remainder of 21.
Record the quotient 1 as the next digit in the result. 
Result so far: 581.0
Subtracting 90 from 111 leaves us with 21.
Bring next digit (7) of the dividend behind the 21 and repeat the process: 217 / 90

Going ahead to step 6:
When dividing 217 by 90, we get 2 with a remainder of 37.
Record the quotient 2 as the next digit in the result. 
Result so far: 5812.0
Deduct 180 from 217 and we're left with 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Let's proceed to step 7:
90 can be fit into 370 4 times, resulting in a remainder of 10.
Use 4 as the next digit of our solution. 
Result so far: 5812.4
If we subtract 360 from 370, we 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.

Moving on to step 8:
100 divided by 90 is 1 with a remainder of 10.
Write down 1 as next digit of the result. 
Result so far: 5812.41
If we take 90 away from 100, 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.

Let's proceed to step 9:
The number 90 fits into 100 1 times, leaving a remainder of 10.
Use 1 as the next digit of our solution. 
Result so far: 5812.411
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.

The final outcome is 5812.411, with a leftover of 0.001.