Let's divide 843999 by 21
Let's see how many times 21 fits into 843999.

Let's proceed to step 1:
21 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
If we take 0 away from 8, we end up with 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 21

Let's proceed to step 2:
When dividing 84 by 21, we get 4 with a remainder of 0.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we subtract 84 from 84, we get 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 21

Advancing to step 3:
3 divided by 21 is 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 40.0
If we take 0 away from 3, we end up with 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 21

Step 4:
The number 21 fits into 39 1 times, leaving a remainder of 18.
Write down 1 as next digit of the result. 
Result so far: 401.0
Subtract 21 from 39 to get 18.
Grab the next digit (9) from the dividend, add it to 18, then carry on: 189 / 21

Moving on to step 5:
21 can be fit into 189 9 times, resulting in a remainder of 0.
Put 9 as the next digit of the answer. 
Result so far: 4019.0
Deduct 189 from 189 and we're left with 0.
Fetch the next digit (9) from the dividend, attach it to 0 and continue: 9 / 21

Going ahead to step 6:
9 divided by 21 is 0 with a remainder of 9.
Put 0 as the next digit of the answer. 
Result so far: 40190.0
The remainder is 9 after subtracting 0 from 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 7:
90 divided by 21 is 4 with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 40190.4
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 40190.42
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 9:
When dividing 180 by 21, we get 8 with a remainder of 12.
The next digit of our result is 8. 
Result so far: 40190.428
If we subtract 168 from 180, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 10:
When dividing 120 by 21, we get 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 40190.4285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 11:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 40190.42857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 12:
21 goes into 30 1 times with a remainder of 9.
The next digit of our result is 1. 
Result so far: 40190.428571
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 13:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 40190.4285714
If we subtract 84 from 90, 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.

Moving on to step 14:
60 divided by 21 is 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 40190.42857142
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Our division results in 40190.42857142 with a remaining 1.8e-08.