509645 divided by 20 
We want to divide 509645 by 20.

Moving on to step 1:
The number 20 fits into 5 0 times, leaving a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Grab the next digit (0) from the dividend, add it to 5, then carry on: 50 / 20

Step 2:
20 goes into 50 2 times with a remainder of 10.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtracting 40 from 50 leaves us with 10.
Fetch the next digit (9) from the dividend, attach it to 10 and continue: 109 / 20

Let's proceed to step 3:
20 goes into 109 5 times with a remainder of 9.
Record the quotient 5 as the next digit in the result. 
Result so far: 25.0
Deduct 100 from 109 and we're left with 9.
Bring next digit (6) of the dividend behind the 9 and repeat the process: 96 / 20

On to step 4:
The number 20 fits into 96 4 times, leaving a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 254.0
Subtracting 80 from 96 leaves us with 16.
Append the next digit (4) from the dividend to 16 and continue with: 164 / 20

On to step 5:
20 can be fit into 164 8 times, resulting in a remainder of 4.
Use 8 as the next digit of our solution. 
Result so far: 2548.0
If we subtract 160 from 164, we get 4.
Bring next digit (5) of the dividend behind the 4 and repeat the process: 45 / 20

Going ahead to step 6:
20 goes into 45 2 times with a remainder of 5.
Put 2 as the next digit of the answer. 
Result so far: 25482.0
Subtracting 40 from 45 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 7:
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: 25482.2
The remainder is 10 after subtracting 40 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 8:
The number 20 fits into 100 5 times, leaving a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 25482.25
Deduct 100 from 100 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.

Advancing to step 9:
The number 20 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 25482.25
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.

Let's proceed to step 10:
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: 25482.25
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 25482.25, with a leftover of 0.0.