We look at the division of 515096 by 90 
The aim is to understand the frequency of 90 in 515096.

Advancing to step 1:
90 can be fit into 5 0 times, resulting in a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Bring next digit (1) of the dividend behind the 5 and repeat the process: 51 / 90

Advancing to step 2:
51 divided by 90 is 0 with a remainder of 51.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 51 to get 51.
Include the next digit (5) from the dividend after 51, then repeat: 515 / 90

Advancing to step 3:
When dividing 515 by 90, we get 5 with a remainder of 65.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
Subtracting 450 from 515 leaves us with 65.
Append the next digit (0) from the dividend to 65 and continue with: 650 / 90

Let's proceed to step 4:
90 can be fit into 650 7 times, resulting in a remainder of 20.
Record the quotient 7 as the next digit in the result. 
Result so far: 57.0
If we subtract 630 from 650, we get 20.
Grab the next digit (9) from the dividend, add it to 20, then carry on: 209 / 90

On to step 5:
The number 90 fits into 209 2 times, leaving a remainder of 29.
The next digit of our result is 2. 
Result so far: 572.0
If we subtract 180 from 209, we get 29.
Grab the next digit (6) from the dividend, add it to 29, then carry on: 296 / 90

Moving on to step 6:
The number 90 fits into 296 3 times, leaving a remainder of 26.
Use 3 as the next digit of our solution. 
Result so far: 5723.0
Subtract 270 from 296 to get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Step 7:
When dividing 260 by 90, we get 2 with a remainder of 80.
Put 2 as the next digit of the answer. 
Result so far: 5723.2
If we subtract 180 from 260, we get 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

On to step 8:
90 can be fit into 800 8 times, resulting in a remainder of 80.
The number 8 becomes the next digit in our result. 
Result so far: 5723.28
If we take 720 away from 800, we end up with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

On to step 9:
The number 90 fits into 800 8 times, leaving a remainder of 80.
The next digit of our result is 8. 
Result so far: 5723.288
If we take 720 away from 800, we end up with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

The quotient of the division is 5723.288, and the remainder is 0.008.