We look at the division of 768655 by 90 
The aim is to understand the frequency of 90 in 768655.

On to step 1:
If we divide 7 by 90, we get 0 and a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Include the next digit (6) from the dividend after 7, then repeat: 76 / 90

Going ahead to step 2:
The number 90 fits into 76 0 times, leaving a remainder of 76.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 76 to get 76.
Fetch the next digit (8) from the dividend, attach it to 76 and continue: 768 / 90

Moving on to step 3:
768 divided by 90 is 8 with a remainder of 48.
The next digit of our result is 8. 
Result so far: 8.0
Subtracting 720 from 768 leaves us with 48.
Fetch the next digit (6) from the dividend, attach it to 48 and continue: 486 / 90

Advancing to step 4:
90 goes into 486 5 times with a remainder of 36.
Write down 5 as next digit of the result. 
Result so far: 85.0
Subtracting 450 from 486 leaves us with 36.
Grab the next digit (5) from the dividend, add it to 36, then carry on: 365 / 90

Let's proceed to step 5:
90 goes into 365 4 times with a remainder of 5.
The next digit of our result is 4. 
Result so far: 854.0
If we take 360 away from 365, we end up with 5.
Bring next digit (5) of the dividend behind the 5 and repeat the process: 55 / 90

Going ahead to step 6:
The number 90 fits into 55 0 times, leaving a remainder of 55.
Write down 0 as next digit of the result. 
Result so far: 8540.0
If we subtract 0 from 55, we get 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Going ahead to step 7:
550 divided by 90 is 6 with a remainder of 10.
Use 6 as the next digit of our solution. 
Result so far: 8540.6
Subtract 540 from 550 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.

Advancing to step 8:
If we divide 100 by 90, we get 1 and a remainder of 10.
Use 1 as the next digit of our solution. 
Result so far: 8540.61
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.

Going ahead to step 9:
The number 90 fits into 100 1 times, leaving a remainder of 10.
Record the quotient 1 as the next digit in the result. 
Result so far: 8540.611
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 result is 8540.611 with a remainder of 0.001.