We look at the division of 509 by 20 
Let's see how many times 20 fits into 509.

Advancing to step 1:
When dividing 5 by 20, we get 0 with a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Take the next digit (0) from the dividend and append it to 5, then repeat: 50 / 20

Step 2:
If we divide 50 by 20, we get 2 and a remainder of 10.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtract 40 from 50 to get 10.
Take the next digit (9) from the dividend and append it to 10, then repeat: 109 / 20

Step 3:
When dividing 109 by 20, we get 5 with a remainder of 9.
The number 5 becomes the next digit in our result. 
Result so far: 25.0
If we subtract 100 from 109, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 4:
90 divided by 20 is 4 with a remainder of 10.
The number 4 becomes the next digit in our result. 
Result so far: 25.4
If we subtract 80 from 90, we get 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 5:
20 goes into 100 5 times with a remainder of 0.
Use 5 as the next digit of our solution. 
Result so far: 25.45
The remainder is 0 after subtracting 100 from 100.
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 6:
20 goes into 0 0 times with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 25.45
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.

Step 7:
The number 20 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 25.45
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.

The final result is 25.45 with a remainder of 0.0.