We look at the division of 317861 by 21 
We want to divide 317861 by 21.

Step 1:
21 goes into 3 0 times with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Grab the next digit (1) from the dividend, add it to 3, then carry on: 31 / 21

Step 2:
If we divide 31 by 21, we get 1 and a remainder of 10.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 21 from 31 leaves us with 10.
Bring next digit (7) of the dividend behind the 10 and repeat the process: 107 / 21

Let's proceed to step 3:
If we divide 107 by 21, we get 5 and a remainder of 2.
Write down 5 as next digit of the result. 
Result so far: 15.0
If we subtract 105 from 107, we get 2.
Fetch the next digit (8) from the dividend, attach it to 2 and continue: 28 / 21

Advancing to step 4:
The number 21 fits into 28 1 times, leaving a remainder of 7.
Write down 1 as next digit of the result. 
Result so far: 151.0
If we take 21 away from 28, we end up with 7.
Fetch the next digit (6) from the dividend, attach it to 7 and continue: 76 / 21

Let's proceed to step 5:
When dividing 76 by 21, we get 3 with a remainder of 13.
The next digit of our result is 3. 
Result so far: 1513.0
Deduct 63 from 76 and we're left with 13.
Append the next digit (1) from the dividend to 13 and continue with: 131 / 21

Moving on to step 6:
21 goes into 131 6 times with a remainder of 5.
The number 6 becomes the next digit in our result. 
Result so far: 15136.0
Deduct 126 from 131 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 7:
If we divide 50 by 21, we get 2 and a remainder of 8.
The next digit of our result is 2. 
Result so far: 15136.2
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 8:
If we divide 80 by 21, we get 3 and a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 15136.23
Subtracting 63 from 80 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 9:
If we divide 170 by 21, we get 8 and a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 15136.238
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.

Advancing to step 10:
20 divided by 21 is 0 with a remainder of 20.
The next digit of our result is 0. 
Result so far: 15136.238
If we take 0 away from 20, we end up 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.

Moving on to step 11:
If we divide 200 by 21, we get 9 and a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 15136.23809
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.

Advancing to step 12:
The number 21 fits into 110 5 times, leaving a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 15136.238095
Subtracting 105 from 110 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 13:
21 goes into 50 2 times with a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 15136.2380952
Subtract 42 from 50 to get 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 14:
21 goes into 80 3 times with a remainder of 17.
The next digit of our result is 3. 
Result so far: 15136.23809523
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Our division results in 15136.23809523 with a remaining 1.7e-08.