393508 divided by 20 
The aim is to understand the frequency of 20 in 393508.

Advancing to step 1:
The number 20 fits into 3 0 times, leaving a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Grab the next digit (9) from the dividend, add it to 3, then carry on: 39 / 20

Step 2:
20 can be fit into 39 1 times, resulting in a remainder of 19.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 20 from 39 and we're left with 19.
Bring next digit (3) of the dividend behind the 19 and repeat the process: 193 / 20

Going ahead to step 3:
If we divide 193 by 20, we get 9 and a remainder of 13.
Write down 9 as next digit of the result. 
Result so far: 19.0
Deduct 180 from 193 and we're left with 13.
Grab the next digit (5) from the dividend, add it to 13, then carry on: 135 / 20

Moving on to step 4:
The number 20 fits into 135 6 times, leaving a remainder of 15.
Put 6 as the next digit of the answer. 
Result so far: 196.0
If we take 120 away from 135, we end up with 15.
Grab the next digit (0) from the dividend, add it to 15, then carry on: 150 / 20

Going ahead to step 5:
20 goes into 150 7 times with a remainder of 10.
Put 7 as the next digit of the answer. 
Result so far: 1967.0
Subtract 140 from 150 to get 10.
Fetch the next digit (8) from the dividend, attach it to 10 and continue: 108 / 20

Step 6:
20 goes into 108 5 times with a remainder of 8.
Write down 5 as next digit of the result. 
Result so far: 19675.0
Subtract 100 from 108 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 7:
If we divide 80 by 20, we get 4 and a remainder of 0.
Record the quotient 4 as the next digit in the result. 
Result so far: 19675.4
The remainder is 0 after subtracting 80 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
If we divide 0 by 20, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 19675.4
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 9:
0 divided by 20 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 19675.4
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 19675.4, with a leftover of 0.0.