We're dividing 612577 by 90 
The aim is to understand the frequency of 90 in 612577.

On to step 1:
90 can be fit into 6 0 times, resulting in a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (1) from the dividend after 6, then repeat: 61 / 90

Advancing to step 2:
61 divided by 90 is 0 with a remainder of 61.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 61, we get 61.
Append the next digit (2) from the dividend to 61 and continue with: 612 / 90

Going ahead to step 3:
If we divide 612 by 90, we get 6 and a remainder of 72.
Put 6 as the next digit of the answer. 
Result so far: 6.0
The remainder is 72 after subtracting 540 from 612.
Bring next digit (5) of the dividend behind the 72 and repeat the process: 725 / 90

Going ahead to step 4:
The number 90 fits into 725 8 times, leaving a remainder of 5.
The next digit of our result is 8. 
Result so far: 68.0
Subtract 720 from 725 to get 5.
Include the next digit (7) from the dividend after 5, then repeat: 57 / 90

Step 5:
If we divide 57 by 90, we get 0 and a remainder of 57.
The next digit of our result is 0. 
Result so far: 680.0
If we subtract 0 from 57, we get 57.
Append the next digit (7) from the dividend to 57 and continue with: 577 / 90

Going ahead to step 6:
90 can be fit into 577 6 times, resulting in a remainder of 37.
The next digit of our result is 6. 
Result so far: 6806.0
If we subtract 540 from 577, we get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Moving on to step 7:
When dividing 370 by 90, we get 4 with a remainder of 10.
Write down 4 as next digit of the result. 
Result so far: 6806.4
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.

Going ahead to step 8:
When dividing 100 by 90, we get 1 with a remainder of 10.
Record the quotient 1 as the next digit in the result. 
Result so far: 6806.41
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.
Use 1 as the next digit of our solution. 
Result so far: 6806.411
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.

The final outcome is 6806.411, with a leftover of 0.001.