Let's divide 307090 by 18
The aim is to understand the frequency of 18 in 307090.

Going ahead to step 1:
The number 18 fits into 3 0 times, leaving a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Grab the next digit (0) from the dividend, add it to 3, then carry on: 30 / 18

Step 2:
18 can be fit into 30 1 times, resulting in a remainder of 12.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtracting 18 from 30 leaves us with 12.
Bring next digit (7) of the dividend behind the 12 and repeat the process: 127 / 18

Going ahead to step 3:
When dividing 127 by 18, we get 7 with a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 17.0
Subtract 126 from 127 to get 1.
Fetch the next digit (0) from the dividend, attach it to 1 and continue: 10 / 18

On to step 4:
18 can be fit into 10 0 times, resulting in a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 170.0
If we subtract 0 from 10, we get 10.
Include the next digit (9) from the dividend after 10, then repeat: 109 / 18

Step 5:
When dividing 109 by 18, we get 6 with a remainder of 1.
Write down 6 as next digit of the result. 
Result so far: 1706.0
If we subtract 108 from 109, we get 1.
Fetch the next digit (0) from the dividend, attach it to 1 and continue: 10 / 18

Step 6:
If we divide 10 by 18, we get 0 and a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 17060.0
If we subtract 0 from 10, we 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.

Let's proceed to step 7:
When dividing 100 by 18, we get 5 with a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 17060.5
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.

Moving on to step 8:
18 can be fit into 100 5 times, resulting in a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 17060.55
Subtract 90 from 100 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.

The final result is 17060.55 with a remainder of 0.01.