We look at the division of 856020 by 90 
The aim is to understand the frequency of 90 in 856020.

Step 1:
90 can be fit into 8 0 times, resulting in a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Fetch the next digit (5) from the dividend, attach it to 8 and continue: 85 / 90

Let's proceed to step 2:
85 divided by 90 is 0 with a remainder of 85.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 85 and we're left with 85.
Take the next digit (6) from the dividend and append it to 85, then repeat: 856 / 90

Step 3:
90 can be fit into 856 9 times, resulting in a remainder of 46.
The next digit of our result is 9. 
Result so far: 9.0
If we take 810 away from 856, we end up with 46.
Take the next digit (0) from the dividend and append it to 46, then repeat: 460 / 90

Step 4:
If we divide 460 by 90, we get 5 and a remainder of 10.
The next digit of our result is 5. 
Result so far: 95.0
The remainder is 10 after subtracting 450 from 460.
Take the next digit (2) from the dividend and append it to 10, then repeat: 102 / 90

Step 5:
102 divided by 90 is 1 with a remainder of 12.
Write down 1 as next digit of the result. 
Result so far: 951.0
Subtract 90 from 102 to get 12.
Include the next digit (0) from the dividend after 12, then repeat: 120 / 90

Advancing to step 6:
90 goes into 120 1 times with a remainder of 30.
Use 1 as the next digit of our solution. 
Result so far: 9511.0
If we subtract 90 from 120, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Advancing to step 7:
90 goes into 300 3 times with a remainder of 30.
Write down 3 as next digit of the result. 
Result so far: 9511.3
Subtract 270 from 300 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Moving on to step 8:
When dividing 300 by 90, we get 3 with a remainder of 30.
Use 3 as the next digit of our solution. 
Result so far: 9511.33
The remainder is 30 after subtracting 270 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

The final result is 9511.33 with a remainder of 0.03.