We're dividing 423950 by 21 
Let's see how many times 21 fits into 423950.

Moving on to step 1:
4 divided by 21 is 0 with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 21

Advancing to step 2:
42 divided by 21 is 2 with a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
The remainder is 0 after subtracting 42 from 42.
Append the next digit (3) from the dividend to 0 and continue with: 3 / 21

Let's proceed to step 3:
21 goes into 3 0 times with a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 20.0
Subtracting 0 from 3 leaves us with 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 21

Going ahead to step 4:
If we divide 39 by 21, we get 1 and a remainder of 18.
The number 1 becomes the next digit in our result. 
Result so far: 201.0
Deduct 21 from 39 and we're left with 18.
Bring next digit (5) of the dividend behind the 18 and repeat the process: 185 / 21

Step 5:
When dividing 185 by 21, we get 8 with a remainder of 17.
Use 8 as the next digit of our solution. 
Result so far: 2018.0
If we take 168 away from 185, we end up with 17.
Grab the next digit (0) from the dividend, add it to 17, then carry on: 170 / 21

Step 6:
If we divide 170 by 21, we get 8 and a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 20188.0
Subtracting 168 from 170 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
21 can be fit into 20 0 times, resulting in a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 20188.0
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 8:
When dividing 200 by 21, we get 9 with a remainder of 11.
The next digit of our result is 9. 
Result so far: 20188.09
Deduct 189 from 200 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 9:
If we divide 110 by 21, we get 5 and a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 20188.095
Subtracting 105 from 110 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.

Going ahead to step 10:
21 goes into 50 2 times with a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 20188.0952
Deduct 42 from 50 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 11:
When dividing 80 by 21, we get 3 with a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 20188.09523
Subtracting 63 from 80 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 12:
21 goes into 170 8 times with a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 20188.095238
If we take 168 away from 170, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 13:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 20188.095238
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 14:
When dividing 200 by 21, we get 9 with a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 20188.09523809
If we take 189 away from 200, we end up 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.

The quotient of the division is 20188.09523809, and the remainder is 1.1e-08.