We divide 430737 by 21
We're looking to find how many times 21 goes into 430737.

Step 1:
The number 21 fits into 4 0 times, leaving a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Include the next digit (3) from the dividend after 4, then repeat: 43 / 21

Let's proceed to step 2:
21 can be fit into 43 2 times, resulting in a remainder of 1.
Put 2 as the next digit of the answer. 
Result so far: 2.0
The remainder is 1 after subtracting 42 from 43.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 21

Let's proceed to step 3:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 20.0
Subtracting 0 from 10 leaves us with 10.
Append the next digit (7) from the dividend to 10 and continue with: 107 / 21

Advancing to step 4:
When dividing 107 by 21, we get 5 with a remainder of 2.
Write down 5 as next digit of the result. 
Result so far: 205.0
Subtract 105 from 107 to get 2.
Fetch the next digit (3) from the dividend, attach it to 2 and continue: 23 / 21

Advancing to step 5:
21 can be fit into 23 1 times, resulting in a remainder of 2.
The next digit of our result is 1. 
Result so far: 2051.0
If we take 21 away from 23, we end up with 2.
Fetch the next digit (7) from the dividend, attach it to 2 and continue: 27 / 21

Going ahead to step 6:
21 goes into 27 1 times with a remainder of 6.
The next digit of our result is 1. 
Result so far: 20511.0
Deduct 21 from 27 and we're left with 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 7:
60 divided by 21 is 2 with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 20511.2
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.

Going ahead to step 8:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 20511.28
Deduct 168 from 180 and we're left 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.

Moving on to step 9:
If we divide 120 by 21, we get 5 and a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 20511.285
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.

Moving on to step 10:
21 goes into 150 7 times with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 20511.2857
If we take 147 away from 150, we end up 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 11:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 20511.28571
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.

Advancing to step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 20511.285714
Subtract 84 from 90 to 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 13:
21 goes into 60 2 times with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 20511.2857142
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.

Moving on to step 14:
If we divide 180 by 21, we get 8 and a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 20511.28571428
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.

In conclusion, the division gives 20511.28571428 with a balance of 1.2e-08.