425415 divided by 18 
The aim is to understand the frequency of 18 in 425415.

Moving on to step 1:
When dividing 4 by 18, we get 0 with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Take the next digit (2) from the dividend and append it to 4, then repeat: 42 / 18

On to step 2:
The number 18 fits into 42 2 times, leaving a remainder of 6.
The next digit of our result is 2. 
Result so far: 2.0
Subtract 36 from 42 to get 6.
Append the next digit (5) from the dividend to 6 and continue with: 65 / 18

On to step 3:
When dividing 65 by 18, we get 3 with a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 23.0
Subtracting 54 from 65 leaves us with 11.
Append the next digit (4) from the dividend to 11 and continue with: 114 / 18

Let's proceed to step 4:
When dividing 114 by 18, we get 6 with a remainder of 6.
The next digit of our result is 6. 
Result so far: 236.0
Subtract 108 from 114 to get 6.
Append the next digit (1) from the dividend to 6 and continue with: 61 / 18

Going ahead to step 5:
If we divide 61 by 18, we get 3 and a remainder of 7.
Put 3 as the next digit of the answer. 
Result so far: 2363.0
If we take 54 away from 61, we end up with 7.
Include the next digit (5) from the dividend after 7, then repeat: 75 / 18

Advancing to step 6:
18 goes into 75 4 times with a remainder of 3.
Put 4 as the next digit of the answer. 
Result so far: 23634.0
If we take 72 away from 75, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 7:
30 divided by 18 is 1 with a remainder of 12.
Put 1 as the next digit of the answer. 
Result so far: 23634.1
The remainder is 12 after subtracting 18 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 8:
If we divide 120 by 18, we get 6 and a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 23634.16
Subtract 108 from 120 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 9:
120 divided by 18 is 6 with a remainder of 12.
The number 6 becomes the next digit in our result. 
Result so far: 23634.166
Deduct 108 from 120 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final outcome is 23634.166, with a leftover of 0.0012.