428647 divided by 21 
We want to divide 428647 by 21.

Step 1:
The number 21 fits into 4 0 times, leaving a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Grab the next digit (2) from the dividend, add it to 4, then carry on: 42 / 21

Step 2:
42 divided by 21 is 2 with a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 42 away from 42, we end up with 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 21

Step 3:
8 divided by 21 is 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 20.0
If we subtract 0 from 8, we get 8.
Bring next digit (6) of the dividend behind the 8 and repeat the process: 86 / 21

Moving on to step 4:
21 goes into 86 4 times with a remainder of 2.
Put 4 as the next digit of the answer. 
Result so far: 204.0
Subtract 84 from 86 to get 2.
Append the next digit (4) from the dividend to 2 and continue with: 24 / 21

Moving on to step 5:
If we divide 24 by 21, we get 1 and a remainder of 3.
Record the quotient 1 as the next digit in the result. 
Result so far: 2041.0
The remainder is 3 after subtracting 21 from 24.
Take the next digit (7) from the dividend and append it to 3, then repeat: 37 / 21

Step 6:
37 divided by 21 is 1 with a remainder of 16.
Write down 1 as next digit of the result. 
Result so far: 20411.0
Subtract 21 from 37 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 7:
21 goes into 160 7 times with a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 20411.7
If we take 147 away from 160, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 8:
If we divide 130 by 21, we get 6 and a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 20411.76
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 9:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 20411.761
Subtract 21 from 40 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Moving on to step 10:
21 goes into 190 9 times with a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 20411.7619
If we subtract 189 from 190, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 11:
If we divide 10 by 21, we get 0 and a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 20411.7619
If we subtract 0 from 10, we get 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 12:
21 goes into 100 4 times with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 20411.761904
If we subtract 84 from 100, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 13:
160 divided by 21 is 7 with a remainder of 13.
The next digit of our result is 7. 
Result so far: 20411.7619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 14:
21 goes into 130 6 times with a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 20411.76190476
If we subtract 126 from 130, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

After the division, we end up with 20411.76190476 and a remainder of 4e-09.