504240 ÷ 20 
We want to divide 504240 by 20.

Step 1:
When dividing 5 by 20, we get 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Take the next digit (0) from the dividend and append it to 5, then repeat: 50 / 20

Moving on to step 2:
20 can be fit into 50 2 times, resulting in a remainder of 10.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Deduct 40 from 50 and we're left with 10.
Fetch the next digit (4) from the dividend, attach it to 10 and continue: 104 / 20

Moving on to step 3:
104 divided by 20 is 5 with a remainder of 4.
The next digit of our result is 5. 
Result so far: 25.0
The remainder is 4 after subtracting 100 from 104.
Append the next digit (2) from the dividend to 4 and continue with: 42 / 20

Moving on to step 4:
42 divided by 20 is 2 with a remainder of 2.
Put 2 as the next digit of the answer. 
Result so far: 252.0
Deduct 40 from 42 and we're left with 2.
Append the next digit (4) from the dividend to 2 and continue with: 24 / 20

On to step 5:
20 can be fit into 24 1 times, resulting in a remainder of 4.
Use 1 as the next digit of our solution. 
Result so far: 2521.0
Subtract 20 from 24 to get 4.
Bring next digit (0) of the dividend behind the 4 and repeat the process: 40 / 20

Going ahead to step 6:
20 goes into 40 2 times with a remainder of 0.
Use 2 as the next digit of our solution. 
Result so far: 25212.0
Deduct 40 from 40 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.

Step 7:
When dividing 0 by 20, we get 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 25212.0
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.

Let's proceed to step 8:
20 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 25212.0
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.

The final outcome is 25212.0, with a leftover of 0.0.