309086 ÷ 90 
The aim is to understand the frequency of 90 in 309086.

Moving on to step 1:
The number 90 fits into 3 0 times, leaving a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Fetch the next digit (0) from the dividend, attach it to 3 and continue: 30 / 90

Advancing to step 2:
30 divided by 90 is 0 with a remainder of 30.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 30 and we're left with 30.
Include the next digit (9) from the dividend after 30, then repeat: 309 / 90

Going ahead to step 3:
If we divide 309 by 90, we get 3 and a remainder of 39.
The next digit of our result is 3. 
Result so far: 3.0
Subtracting 270 from 309 leaves us with 39.
Bring next digit (0) of the dividend behind the 39 and repeat the process: 390 / 90

Going ahead to step 4:
If we divide 390 by 90, we get 4 and a remainder of 30.
Use 4 as the next digit of our solution. 
Result so far: 34.0
Subtracting 360 from 390 leaves us with 30.
Grab the next digit (8) from the dividend, add it to 30, then carry on: 308 / 90

Step 5:
If we divide 308 by 90, we get 3 and a remainder of 38.
Use 3 as the next digit of our solution. 
Result so far: 343.0
Subtracting 270 from 308 leaves us with 38.
Fetch the next digit (6) from the dividend, attach it to 38 and continue: 386 / 90

On to step 6:
The number 90 fits into 386 4 times, leaving a remainder of 26.
The next digit of our result is 4. 
Result so far: 3434.0
Subtract 360 from 386 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.

Let's proceed to step 7:
The number 90 fits into 260 2 times, leaving a remainder of 80.
The next digit of our result is 2. 
Result so far: 3434.2
Deduct 180 from 260 and we're left 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 8:
If we divide 800 by 90, we get 8 and a remainder of 80.
Put 8 as the next digit of the answer. 
Result so far: 3434.28
Subtract 720 from 800 to 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.

Let's proceed to step 9:
800 divided by 90 is 8 with a remainder of 80.
Record the quotient 8 as the next digit in the result. 
Result so far: 3434.288
Deduct 720 from 800 and we're left 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.

Our division results in 3434.288 with a remaining 0.008.