We look at the division of 770694 by 90 
The aim is to understand the frequency of 90 in 770694.

Let's proceed to step 1:
When dividing 7 by 90, we get 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Take the next digit (7) from the dividend and append it to 7, then repeat: 77 / 90

Let's proceed to step 2:
The number 90 fits into 77 0 times, leaving a remainder of 77.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 77 and we're left with 77.
Fetch the next digit (0) from the dividend, attach it to 77 and continue: 770 / 90

On to step 3:
The number 90 fits into 770 8 times, leaving a remainder of 50.
Use 8 as the next digit of our solution. 
Result so far: 8.0
If we subtract 720 from 770, we get 50.
Take the next digit (6) from the dividend and append it to 50, then repeat: 506 / 90

Going ahead to step 4:
When dividing 506 by 90, we get 5 with a remainder of 56.
Record the quotient 5 as the next digit in the result. 
Result so far: 85.0
If we subtract 450 from 506, we get 56.
Include the next digit (9) from the dividend after 56, then repeat: 569 / 90

On to step 5:
If we divide 569 by 90, we get 6 and a remainder of 29.
Put 6 as the next digit of the answer. 
Result so far: 856.0
If we take 540 away from 569, we end up with 29.
Take the next digit (4) from the dividend and append it to 29, then repeat: 294 / 90

Moving on to step 6:
If we divide 294 by 90, we get 3 and a remainder of 24.
Write down 3 as next digit of the result. 
Result so far: 8563.0
Deduct 270 from 294 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Moving on to step 7:
90 can be fit into 240 2 times, resulting in a remainder of 60.
Use 2 as the next digit of our solution. 
Result so far: 8563.2
The remainder is 60 after subtracting 180 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

On to step 8:
When dividing 600 by 90, we get 6 with a remainder of 60.
Record the quotient 6 as the next digit in the result. 
Result so far: 8563.26
If we take 540 away from 600, we end up with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Step 9:
When dividing 600 by 90, we get 6 with a remainder of 60.
Record the quotient 6 as the next digit in the result. 
Result so far: 8563.266
The remainder is 60 after subtracting 540 from 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

The final result is 8563.266 with a remainder of 0.006.