430423 divided by 18 
The aim is to understand the frequency of 18 in 430423.

On to step 1:
18 goes into 4 0 times with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Include the next digit (3) from the dividend after 4, then repeat: 43 / 18

Step 2:
18 goes into 43 2 times with a remainder of 7.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 36 away from 43, we end up with 7.
Bring next digit (0) of the dividend behind the 7 and repeat the process: 70 / 18

Advancing to step 3:
18 goes into 70 3 times with a remainder of 16.
The number 3 becomes the next digit in our result. 
Result so far: 23.0
If we subtract 54 from 70, we get 16.
Bring next digit (4) of the dividend behind the 16 and repeat the process: 164 / 18

Moving on to step 4:
18 goes into 164 9 times with a remainder of 2.
Write down 9 as next digit of the result. 
Result so far: 239.0
Deduct 162 from 164 and we're left with 2.
Append the next digit (2) from the dividend to 2 and continue with: 22 / 18

Going ahead to step 5:
If we divide 22 by 18, we get 1 and a remainder of 4.
Record the quotient 1 as the next digit in the result. 
Result so far: 2391.0
The remainder is 4 after subtracting 18 from 22.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 18

Step 6:
43 divided by 18 is 2 with a remainder of 7.
Use 2 as the next digit of our solution. 
Result so far: 23912.0
The remainder is 7 after subtracting 36 from 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Step 7:
70 divided by 18 is 3 with a remainder of 16.
Put 3 as the next digit of the answer. 
Result so far: 23912.3
If we take 54 away from 70, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 8:
If we divide 160 by 18, we get 8 and a remainder of 16.
Use 8 as the next digit of our solution. 
Result so far: 23912.38
The remainder is 16 after subtracting 144 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 9:
The number 18 fits into 160 8 times, leaving a remainder of 16.
Use 8 as the next digit of our solution. 
Result so far: 23912.388
Deduct 144 from 160 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final result is 23912.388 with a remainder of 0.0016.