We look at the division of 313842 by 21 
We want to divide 313842 by 21.

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.
Take the next digit (1) from the dividend and append it to 3, then repeat: 31 / 21

On to step 2:
The number 21 fits into 31 1 times, leaving a remainder of 10.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 21 from 31 and we're left with 10.
Append the next digit (3) from the dividend to 10 and continue with: 103 / 21

Advancing to step 3:
103 divided by 21 is 4 with a remainder of 19.
Record the quotient 4 as the next digit in the result. 
Result so far: 14.0
Deduct 84 from 103 and we're left with 19.
Append the next digit (8) from the dividend to 19 and continue with: 198 / 21

Advancing to step 4:
21 goes into 198 9 times with a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 149.0
Subtracting 189 from 198 leaves us with 9.
Include the next digit (4) from the dividend after 9, then repeat: 94 / 21

On to step 5:
The number 21 fits into 94 4 times, leaving a remainder of 10.
The next digit of our result is 4. 
Result so far: 1494.0
Subtracting 84 from 94 leaves us with 10.
Fetch the next digit (2) from the dividend, attach it to 10 and continue: 102 / 21

Let's proceed to step 6:
21 can be fit into 102 4 times, resulting in a remainder of 18.
Use 4 as the next digit of our solution. 
Result so far: 14944.0
The remainder is 18 after subtracting 84 from 102.
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 7:
If we divide 180 by 21, we get 8 and a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 14944.8
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 8:
120 divided by 21 is 5 with a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 14944.85
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 9:
If we divide 150 by 21, we get 7 and a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 14944.857
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.

Moving on to step 10:
When dividing 30 by 21, we get 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 14944.8571
If we take 21 away from 30, we end up 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.

Advancing to step 11:
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: 14944.85714
Deduct 84 from 90 and we're left 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.

Step 12:
21 goes into 60 2 times with a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 14944.857142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Step 13:
If we divide 180 by 21, we get 8 and a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 14944.8571428
If we subtract 168 from 180, we get 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 14:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 14944.85714285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The final result is 14944.85714285 with a remainder of 1.5e-08.