We look at the division of 406470 by 21 
Our goal is to divide 406470 by 21.

Going ahead to step 1:
4 divided by 21 is 0 with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Include the next digit (0) from the dividend after 4, then repeat: 40 / 21

Advancing to step 2:
40 divided by 21 is 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 1.0
The remainder is 19 after subtracting 21 from 40.
Bring next digit (6) of the dividend behind the 19 and repeat the process: 196 / 21

Let's proceed to step 3:
21 can be fit into 196 9 times, resulting in a remainder of 7.
The next digit of our result is 9. 
Result so far: 19.0
Deduct 189 from 196 and we're left with 7.
Take the next digit (4) from the dividend and append it to 7, then repeat: 74 / 21

Let's proceed to step 4:
21 can be fit into 74 3 times, resulting in a remainder of 11.
Use 3 as the next digit of our solution. 
Result so far: 193.0
Subtract 63 from 74 to get 11.
Fetch the next digit (7) from the dividend, attach it to 11 and continue: 117 / 21

On to step 5:
When dividing 117 by 21, we get 5 with a remainder of 12.
Use 5 as the next digit of our solution. 
Result so far: 1935.0
If we take 105 away from 117, we end up with 12.
Append the next digit (0) from the dividend to 12 and continue with: 120 / 21

On to step 6:
21 goes into 120 5 times with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 19355.0
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 7:
The number 21 fits into 150 7 times, leaving a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 19355.7
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 8:
30 divided by 21 is 1 with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 19355.71
Deduct 21 from 30 and we're left with 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 9:
When dividing 90 by 21, we get 4 with a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 19355.714
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.

Step 10:
60 divided by 21 is 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 19355.7142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 11:
21 goes into 180 8 times with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 19355.71428
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 12:
21 goes into 120 5 times with a remainder of 15.
The next digit of our result is 5. 
Result so far: 19355.714285
Subtracting 105 from 120 leaves us 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 13:
150 divided by 21 is 7 with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 19355.7142857
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 14:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 19355.71428571
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.

Our division results in 19355.71428571 with a remaining 9e-09.