Let's divide 172588 by 18
The aim is to understand the frequency of 18 in 172588.

Going ahead to step 1:
18 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Grab the next digit (7) from the dividend, add it to 1, then carry on: 17 / 18

Advancing to step 2:
18 goes into 17 0 times with a remainder of 17.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 17 after subtracting 0 from 17.
Include the next digit (2) from the dividend after 17, then repeat: 172 / 18

On to step 3:
The number 18 fits into 172 9 times, leaving a remainder of 10.
Record the quotient 9 as the next digit in the result. 
Result so far: 9.0
The remainder is 10 after subtracting 162 from 172.
Fetch the next digit (5) from the dividend, attach it to 10 and continue: 105 / 18

Moving on to step 4:
18 goes into 105 5 times with a remainder of 15.
The next digit of our result is 5. 
Result so far: 95.0
The remainder is 15 after subtracting 90 from 105.
Fetch the next digit (8) from the dividend, attach it to 15 and continue: 158 / 18

Step 5:
The number 18 fits into 158 8 times, leaving a remainder of 14.
Record the quotient 8 as the next digit in the result. 
Result so far: 958.0
If we subtract 144 from 158, we get 14.
Include the next digit (8) from the dividend after 14, then repeat: 148 / 18

Advancing to step 6:
18 can be fit into 148 8 times, resulting in a remainder of 4.
Write down 8 as next digit of the result. 
Result so far: 9588.0
If we subtract 144 from 148, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 7:
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: 9588.2
Subtracting 36 from 40 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.

Let's proceed to step 8:
If we divide 40 by 18, we get 2 and a remainder of 4.
Write down 2 as next digit of the result. 
Result so far: 9588.22
If we subtract 36 from 40, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

After the division, we end up with 9588.22 and a remainder of 0.004.