We look at the division of 405963 by 20 
The aim is to understand the frequency of 20 in 405963.

Going ahead to step 1:
4 divided by 20 is 0 with a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Fetch the next digit (0) from the dividend, attach it to 4 and continue: 40 / 20

Advancing to step 2:
40 divided by 20 is 2 with a remainder of 0.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 40 away from 40, we end up with 0.
Append the next digit (5) from the dividend to 0 and continue with: 5 / 20

Let's proceed to step 3:
20 can be fit into 5 0 times, resulting in a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 20.0
Subtracting 0 from 5 leaves us with 5.
Include the next digit (9) from the dividend after 5, then repeat: 59 / 20

Let's proceed to step 4:
59 divided by 20 is 2 with a remainder of 19.
Write down 2 as next digit of the result. 
Result so far: 202.0
If we take 40 away from 59, we end up with 19.
Take the next digit (6) from the dividend and append it to 19, then repeat: 196 / 20

Going ahead to step 5:
The number 20 fits into 196 9 times, leaving a remainder of 16.
The number 9 becomes the next digit in our result. 
Result so far: 2029.0
Subtracting 180 from 196 leaves us with 16.
Grab the next digit (3) from the dividend, add it to 16, then carry on: 163 / 20

Step 6:
When dividing 163 by 20, we get 8 with a remainder of 3.
The next digit of our result is 8. 
Result so far: 20298.0
Subtracting 160 from 163 leaves us 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 20 is 1 with a remainder of 10.
Record the quotient 1 as the next digit in the result. 
Result so far: 20298.1
If we take 20 away from 30, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 8:
20 can be fit into 100 5 times, resulting in a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 20298.15
If we take 100 away from 100, we end up 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.

Advancing to step 9:
When dividing 0 by 20, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 20298.15
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 10:
0 divided by 20 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 20298.15
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Our division results in 20298.15 with a remaining 0.0.