We're dividing 455299 by 21 
We're looking to find how many times 21 goes into 455299.

Going ahead to step 1:
When dividing 4 by 21, we get 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Append the next digit (5) from the dividend to 4 and continue with: 45 / 21

Going ahead to step 2:
If we divide 45 by 21, we get 2 and a remainder of 3.
The next digit of our result is 2. 
Result so far: 2.0
Subtracting 42 from 45 leaves us with 3.
Take the next digit (5) from the dividend and append it to 3, then repeat: 35 / 21

On to step 3:
21 goes into 35 1 times with a remainder of 14.
Put 1 as the next digit of the answer. 
Result so far: 21.0
Subtract 21 from 35 to get 14.
Take the next digit (2) from the dividend and append it to 14, then repeat: 142 / 21

Advancing to step 4:
The number 21 fits into 142 6 times, leaving a remainder of 16.
Write down 6 as next digit of the result. 
Result so far: 216.0
Deduct 126 from 142 and we're left with 16.
Grab the next digit (9) from the dividend, add it to 16, then carry on: 169 / 21

Step 5:
21 goes into 169 8 times with a remainder of 1.
Use 8 as the next digit of our solution. 
Result so far: 2168.0
The remainder is 1 after subtracting 168 from 169.
Append the next digit (9) from the dividend to 1 and continue with: 19 / 21

On to step 6:
If we divide 19 by 21, we get 0 and a remainder of 19.
The number 0 becomes the next digit in our result. 
Result so far: 21680.0
Deduct 0 from 19 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.

On to step 7:
When dividing 190 by 21, we get 9 with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 21680.9
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.

Advancing to step 8:
21 goes into 10 0 times with a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 21680.9
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 9:
If we divide 100 by 21, we get 4 and a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 21680.904
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.

Moving on to step 10:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 21680.9047
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.

Going ahead to step 11:
When dividing 130 by 21, we get 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 21680.90476
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.

Going ahead to step 12:
If we divide 40 by 21, we get 1 and a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 21680.904761
If we subtract 21 from 40, we 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.

Step 13:
21 goes into 190 9 times with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 21680.9047619
Deduct 189 from 190 and we're left 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 14:
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: 21680.9047619
Deduct 0 from 10 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final result is 21680.9047619 with a remainder of 1e-08.