Let's divide 428245 by 21
Let's see how many times 21 fits into 428245.

On to step 1:
21 can be fit into 4 0 times, resulting in a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Take the next digit (2) from the dividend and append it to 4, then repeat: 42 / 21

On to step 2:
The number 21 fits into 42 2 times, leaving a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 2.0
The remainder is 0 after subtracting 42 from 42.
Grab the next digit (8) from the dividend, add it to 0, then carry on: 8 / 21

Advancing to step 3:
The number 21 fits into 8 0 times, leaving a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 20.0
The remainder is 8 after subtracting 0 from 8.
Fetch the next digit (2) from the dividend, attach it to 8 and continue: 82 / 21

Going ahead to step 4:
If we divide 82 by 21, we get 3 and a remainder of 19.
Write down 3 as next digit of the result. 
Result so far: 203.0
Subtracting 63 from 82 leaves us with 19.
Include the next digit (4) from the dividend after 19, then repeat: 194 / 21

Moving on to step 5:
If we divide 194 by 21, we get 9 and a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 2039.0
If we subtract 189 from 194, we get 5.
Append the next digit (5) from the dividend to 5 and continue with: 55 / 21

Step 6:
21 goes into 55 2 times with a remainder of 13.
The number 2 becomes the next digit in our result. 
Result so far: 20392.0
Subtracting 42 from 55 leaves us 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.

Moving on to step 7:
21 can be fit into 130 6 times, resulting in a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 20392.6
If we take 126 away from 130, we end up with 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 8:
When dividing 40 by 21, we get 1 with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 20392.61
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.

On to step 9:
21 goes into 190 9 times with a remainder of 1.
The next digit of our result is 9. 
Result so far: 20392.619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 10:
When dividing 10 by 21, we get 0 with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 20392.619
Subtract 0 from 10 to 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.

Moving on to step 11:
When dividing 100 by 21, we get 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 20392.61904
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 12:
160 divided by 21 is 7 with a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 20392.619047
Subtracting 147 from 160 leaves us 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.

Step 13:
130 divided by 21 is 6 with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 20392.6190476
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 14:
40 divided by 21 is 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 20392.61904761
Deduct 21 from 40 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

After the division, we end up with 20392.61904761 and a remainder of 1.9e-08.