We look at the division of 399866 by 20 
We want to divide 399866 by 20.

Advancing to step 1:
The number 20 fits into 3 0 times, leaving a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 20

Let's proceed to step 2:
The number 20 fits into 39 1 times, leaving a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 20 from 39 and we're left with 19.
Take the next digit (9) from the dividend and append it to 19, then repeat: 199 / 20

Let's proceed to step 3:
20 goes into 199 9 times with a remainder of 19.
The next digit of our result is 9. 
Result so far: 19.0
Deduct 180 from 199 and we're left with 19.
Fetch the next digit (8) from the dividend, attach it to 19 and continue: 198 / 20

On to step 4:
20 can be fit into 198 9 times, resulting in a remainder of 18.
Record the quotient 9 as the next digit in the result. 
Result so far: 199.0
Deduct 180 from 198 and we're left with 18.
Append the next digit (6) from the dividend to 18 and continue with: 186 / 20

Advancing to step 5:
186 divided by 20 is 9 with a remainder of 6.
Write down 9 as next digit of the result. 
Result so far: 1999.0
Subtract 180 from 186 to get 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 20

Let's proceed to step 6:
20 can be fit into 66 3 times, resulting in a remainder of 6.
Put 3 as the next digit of the answer. 
Result so far: 19993.0
If we subtract 60 from 66, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 7:
20 goes into 60 3 times with a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 19993.3
If we take 60 away from 60, 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.

On to step 8:
When dividing 0 by 20, we get 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 19993.3
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.

Moving on to step 9:
The number 20 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 19993.3
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 outcome is 19993.3, with a leftover of 0.0.