843191 ÷ 20 
We want to divide 843191 by 20.

On to step 1:
20 can be fit into 8 0 times, resulting in a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Fetch the next digit (4) from the dividend, attach it to 8 and continue: 84 / 20

Moving on to step 2:
20 goes into 84 4 times with a remainder of 4.
Use 4 as the next digit of our solution. 
Result so far: 4.0
The remainder is 4 after subtracting 80 from 84.
Take the next digit (3) from the dividend and append it to 4, then repeat: 43 / 20

Going ahead to step 3:
If we divide 43 by 20, we get 2 and a remainder of 3.
Use 2 as the next digit of our solution. 
Result so far: 42.0
If we take 40 away from 43, we end up with 3.
Take the next digit (1) from the dividend and append it to 3, then repeat: 31 / 20

Moving on to step 4:
If we divide 31 by 20, we get 1 and a remainder of 11.
Use 1 as the next digit of our solution. 
Result so far: 421.0
The remainder is 11 after subtracting 20 from 31.
Bring next digit (9) of the dividend behind the 11 and repeat the process: 119 / 20

Step 5:
20 can be fit into 119 5 times, resulting in a remainder of 19.
Write down 5 as next digit of the result. 
Result so far: 4215.0
If we subtract 100 from 119, we get 19.
Take the next digit (1) from the dividend and append it to 19, then repeat: 191 / 20

Going ahead to step 6:
20 can be fit into 191 9 times, resulting in a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 42159.0
Deduct 180 from 191 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 7:
When dividing 110 by 20, we get 5 with a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 42159.5
Subtracting 100 from 110 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 8:
20 can be fit into 100 5 times, resulting in a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 42159.55
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.

The final outcome is 42159.55, with a leftover of 0.0.