We're dividing 25413 by 20 
The aim is to understand the frequency of 20 in 25413.

On to step 1:
When dividing 2 by 20, we get 0 with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 20

On to step 2:
20 can be fit into 25 1 times, resulting in a remainder of 5.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 20 from 25, we get 5.
Fetch the next digit (4) from the dividend, attach it to 5 and continue: 54 / 20

Advancing to step 3:
54 divided by 20 is 2 with a remainder of 14.
The next digit of our result is 2. 
Result so far: 12.0
The remainder is 14 after subtracting 40 from 54.
Include the next digit (1) from the dividend after 14, then repeat: 141 / 20

Moving on to step 4:
If we divide 141 by 20, we get 7 and a remainder of 1.
The number 7 becomes the next digit in our result. 
Result so far: 127.0
The remainder is 1 after subtracting 140 from 141.
Take the next digit (3) from the dividend and append it to 1, then repeat: 13 / 20

Step 5:
If we divide 13 by 20, we get 0 and a remainder of 13.
Write down 0 as next digit of the result. 
Result so far: 1270.0
If we subtract 0 from 13, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 6:
When dividing 130 by 20, we get 6 with a remainder of 10.
Put 6 as the next digit of the answer. 
Result so far: 1270.6
The remainder is 10 after subtracting 120 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 7:
If we divide 100 by 20, we get 5 and a remainder of 0.
The next digit of our result is 5. 
Result so far: 1270.65
If we subtract 100 from 100, we 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.

Let's proceed to step 8:
If we divide 0 by 20, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 1270.65
If we take 0 away from 0, 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.

Let's proceed to step 9:
The number 20 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 1270.65
If we subtract 0 from 0, we 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.

After the division, we end up with 1270.65 and a remainder of 0.0.