We divide 312006 by 21
We want to figure out the number of times 312006 can be divided by 21.

Moving on to step 1:
21 goes into 3 0 times with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Grab the next digit (1) from the dividend, add it to 3, then carry on: 31 / 21

Advancing to step 2:
The number 21 fits into 31 1 times, leaving a remainder of 10.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we take 21 away from 31, we end up with 10.
Append the next digit (2) from the dividend to 10 and continue with: 102 / 21

Advancing to step 3:
When dividing 102 by 21, we get 4 with a remainder of 18.
Put 4 as the next digit of the answer. 
Result so far: 14.0
Subtracting 84 from 102 leaves us with 18.
Bring next digit (0) of the dividend behind the 18 and repeat the process: 180 / 21

Step 4:
When dividing 180 by 21, we get 8 with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 148.0
Deduct 168 from 180 and we're left with 12.
Take the next digit (0) from the dividend and append it to 12, then repeat: 120 / 21

On to step 5:
When dividing 120 by 21, we get 5 with a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 1485.0
The remainder is 15 after subtracting 105 from 120.
Append the next digit (6) from the dividend to 15 and continue with: 156 / 21

Step 6:
156 divided by 21 is 7 with a remainder of 9.
Put 7 as the next digit of the answer. 
Result so far: 14857.0
Subtracting 147 from 156 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 7:
If we divide 90 by 21, we get 4 and a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 14857.4
If we take 84 away from 90, we end up 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.

Let's proceed to step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The next digit of our result is 2. 
Result so far: 14857.42
If we take 42 away from 60, we end up 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.

Going ahead to step 9:
When dividing 180 by 21, we get 8 with a remainder of 12.
The next digit of our result is 8. 
Result so far: 14857.428
If we take 168 away from 180, we end up 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.

Let's proceed to step 10:
If we divide 120 by 21, we get 5 and a remainder of 15.
The next digit of our result is 5. 
Result so far: 14857.4285
The remainder is 15 after subtracting 105 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

On to step 11:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 14857.42857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 12:
If we divide 30 by 21, we get 1 and a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 14857.428571
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 13:
When dividing 90 by 21, we get 4 with a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 14857.4285714
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.

Going ahead to step 14:
60 divided by 21 is 2 with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 14857.42857142
If we take 42 away from 60, we end up 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.

Our division results in 14857.42857142 with a remaining 1.8e-08.