We look at the division of 437413 by 18 
The aim is to understand the frequency of 18 in 437413.

Let's proceed to step 1:
18 goes into 4 0 times with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 18

Advancing to step 2:
18 goes into 43 2 times with a remainder of 7.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Subtract 36 from 43 to get 7.
Include the next digit (7) from the dividend after 7, then repeat: 77 / 18

On to step 3:
18 can be fit into 77 4 times, resulting in a remainder of 5.
The next digit of our result is 4. 
Result so far: 24.0
Subtracting 72 from 77 leaves us with 5.
Take the next digit (4) from the dividend and append it to 5, then repeat: 54 / 18

Going ahead to step 4:
The number 18 fits into 54 3 times, leaving a remainder of 0.
The number 3 becomes the next digit in our result. 
Result so far: 243.0
Subtracting 54 from 54 leaves us with 0.
Take the next digit (1) from the dividend and append it to 0, then repeat: 1 / 18

Step 5:
1 divided by 18 is 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 2430.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (3) from the dividend to 1 and continue with: 13 / 18

Let's proceed to step 6:
18 can be fit into 13 0 times, resulting in a remainder of 13.
Put 0 as the next digit of the answer. 
Result so far: 24300.0
If we subtract 0 from 13, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 7:
If we divide 130 by 18, we get 7 and a remainder of 4.
The number 7 becomes the next digit in our result. 
Result so far: 24300.7
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 8:
When dividing 40 by 18, we get 2 with a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 24300.72
If we take 36 away from 40, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 9:
18 can be fit into 40 2 times, resulting in a remainder of 4.
Write down 2 as next digit of the result. 
Result so far: 24300.722
Deduct 36 from 40 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final result is 24300.722 with a remainder of 0.0004.