We look at the division of 606668 by 21 
We want to figure out the number of times 606668 can be divided by 21.

Let's proceed to step 1:
6 divided by 21 is 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Append the next digit (0) from the dividend to 6 and continue with: 60 / 21

Going ahead to step 2:
If we divide 60 by 21, we get 2 and a remainder of 18.
The next digit of our result is 2. 
Result so far: 2.0
If we subtract 42 from 60, we get 18.
Fetch the next digit (6) from the dividend, attach it to 18 and continue: 186 / 21

Step 3:
21 can be fit into 186 8 times, resulting in a remainder of 18.
Use 8 as the next digit of our solution. 
Result so far: 28.0
Subtracting 168 from 186 leaves us with 18.
Take the next digit (6) from the dividend and append it to 18, then repeat: 186 / 21

On to step 4:
If we divide 186 by 21, we get 8 and a remainder of 18.
Use 8 as the next digit of our solution. 
Result so far: 288.0
Subtract 168 from 186 to get 18.
Bring next digit (6) of the dividend behind the 18 and repeat the process: 186 / 21

Going ahead to step 5:
21 goes into 186 8 times with a remainder of 18.
The number 8 becomes the next digit in our result. 
Result so far: 2888.0
If we subtract 168 from 186, we get 18.
Fetch the next digit (8) from the dividend, attach it to 18 and continue: 188 / 21

Step 6:
21 can be fit into 188 8 times, resulting in a remainder of 20.
Write down 8 as next digit of the result. 
Result so far: 28888.0
The remainder is 20 after subtracting 168 from 188.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 7:
21 goes into 200 9 times with a remainder of 11.
The next digit of our result is 9. 
Result so far: 28888.9
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 8:
When dividing 110 by 21, we get 5 with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 28888.95
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 9:
21 can be fit into 50 2 times, resulting in a remainder of 8.
The next digit of our result is 2. 
Result so far: 28888.952
Deduct 42 from 50 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 10:
If we divide 80 by 21, we get 3 and a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 28888.9523
Subtract 63 from 80 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 11:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 28888.95238
If we take 168 away from 170, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 12:
20 divided by 21 is 0 with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 28888.95238
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 13:
If we divide 200 by 21, we get 9 and a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 28888.9523809
If we subtract 189 from 200, we get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 14:
21 can be fit into 110 5 times, resulting in a remainder of 5.
The next digit of our result is 5. 
Result so far: 28888.95238095
Subtract 105 from 110 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Our division results in 28888.95238095 with a remaining 5e-09.