409990 divided by 20 
We want to divide 409990 by 20.

Let's proceed to step 1:
If we divide 4 by 20, we get 0 and a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Take the next digit (0) from the dividend and append it to 4, then repeat: 40 / 20

Step 2:
When dividing 40 by 20, we get 2 with a remainder of 0.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 40 from 40 and we're left with 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 20

On to step 3:
9 divided by 20 is 0 with a remainder of 9.
The next digit of our result is 0. 
Result so far: 20.0
Deduct 0 from 9 and we're left with 9.
Fetch the next digit (9) from the dividend, attach it to 9 and continue: 99 / 20

Let's proceed to step 4:
If we divide 99 by 20, we get 4 and a remainder of 19.
Write down 4 as next digit of the result. 
Result so far: 204.0
If we take 80 away from 99, we end up with 19.
Append the next digit (9) from the dividend to 19 and continue with: 199 / 20

On to step 5:
When dividing 199 by 20, we get 9 with a remainder of 19.
The next digit of our result is 9. 
Result so far: 2049.0
If we subtract 180 from 199, we get 19.
Include the next digit (0) from the dividend after 19, then repeat: 190 / 20

Advancing to step 6:
190 divided by 20 is 9 with a remainder of 10.
The next digit of our result is 9. 
Result so far: 20499.0
The remainder is 10 after subtracting 180 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 7:
If we divide 100 by 20, we get 5 and a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 20499.5
If we take 100 away from 100, 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:
20 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 20499.5
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.

Let's proceed to step 9:
20 goes into 0 0 times with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 20499.5
Deduct 0 from 0 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.

After the division, we end up with 20499.5 and a remainder of 0.0.