We look at the division of 918697 by 90 
The aim is to understand the frequency of 90 in 918697.

Let's proceed to step 1:
If we divide 9 by 90, we get 0 and a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Append the next digit (1) from the dividend to 9 and continue with: 91 / 90

Step 2:
If we divide 91 by 90, we get 1 and a remainder of 1.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Deduct 90 from 91 and we're left with 1.
Take the next digit (8) from the dividend and append it to 1, then repeat: 18 / 90

Moving on to step 3:
18 divided by 90 is 0 with a remainder of 18.
Put 0 as the next digit of the answer. 
Result so far: 10.0
Deduct 0 from 18 and we're left with 18.
Append the next digit (6) from the dividend to 18 and continue with: 186 / 90

Advancing to step 4:
When dividing 186 by 90, we get 2 with a remainder of 6.
Write down 2 as next digit of the result. 
Result so far: 102.0
If we take 180 away from 186, we end up with 6.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 90

Advancing to step 5:
When dividing 69 by 90, we get 0 with a remainder of 69.
Put 0 as the next digit of the answer. 
Result so far: 1020.0
The remainder is 69 after subtracting 0 from 69.
Take the next digit (7) from the dividend and append it to 69, then repeat: 697 / 90

Moving on to step 6:
697 divided by 90 is 7 with a remainder of 67.
The next digit of our result is 7. 
Result so far: 10207.0
Subtract 630 from 697 to get 67.
Since there are no more digits in the dividend, we add a zero to the remainder making it 670, and continue the process.

On to step 7:
90 can be fit into 670 7 times, resulting in a remainder of 40.
Put 7 as the next digit of the answer. 
Result so far: 10207.7
Subtract 630 from 670 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 8:
90 can be fit into 400 4 times, resulting in a remainder of 40.
Record the quotient 4 as the next digit in the result. 
Result so far: 10207.74
If we subtract 360 from 400, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Let's proceed to step 9:
90 goes into 400 4 times with a remainder of 40.
Use 4 as the next digit of our solution. 
Result so far: 10207.744
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

The final result is 10207.744 with a remainder of 0.004.