We look at the division of 20588 by 18 
The aim is to understand the frequency of 18 in 20588.

Going ahead to step 1:
18 can be fit into 2 0 times, resulting in a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Fetch the next digit (0) from the dividend, attach it to 2 and continue: 20 / 18

On to step 2:
The number 18 fits into 20 1 times, leaving a remainder of 2.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtract 18 from 20 to get 2.
Fetch the next digit (5) from the dividend, attach it to 2 and continue: 25 / 18

Going ahead to step 3:
25 divided by 18 is 1 with a remainder of 7.
Put 1 as the next digit of the answer. 
Result so far: 11.0
Subtract 18 from 25 to get 7.
Append the next digit (8) from the dividend to 7 and continue with: 78 / 18

Step 4:
78 divided by 18 is 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 114.0
Deduct 72 from 78 and we're left with 6.
Include the next digit (8) from the dividend after 6, then repeat: 68 / 18

Advancing to step 5:
18 goes into 68 3 times with a remainder of 14.
The number 3 becomes the next digit in our result. 
Result so far: 1143.0
The remainder is 14 after subtracting 54 from 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 6:
If we divide 140 by 18, we get 7 and a remainder of 14.
Record the quotient 7 as the next digit in the result. 
Result so far: 1143.7
Deduct 126 from 140 and we're left with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Going ahead to step 7:
If we divide 140 by 18, we get 7 and a remainder of 14.
Write down 7 as next digit of the result. 
Result so far: 1143.77
Subtract 126 from 140 to get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

The final result is 1143.77 with a remainder of 0.014.