We're dividing 360686 by 21 
We're looking to find how many times 21 goes into 360686.

Advancing to step 1:
The number 21 fits into 3 0 times, leaving a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Append the next digit (6) from the dividend to 3 and continue with: 36 / 21

Going ahead to step 2:
If we divide 36 by 21, we get 1 and a remainder of 15.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 15 after subtracting 21 from 36.
Append the next digit (0) from the dividend to 15 and continue with: 150 / 21

Advancing to step 3:
150 divided by 21 is 7 with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 17.0
Deduct 147 from 150 and we're left with 3.
Bring next digit (6) of the dividend behind the 3 and repeat the process: 36 / 21

Moving on to step 4:
21 goes into 36 1 times with a remainder of 15.
The next digit of our result is 1. 
Result so far: 171.0
Deduct 21 from 36 and we're left with 15.
Append the next digit (8) from the dividend to 15 and continue with: 158 / 21

Advancing to step 5:
158 divided by 21 is 7 with a remainder of 11.
Use 7 as the next digit of our solution. 
Result so far: 1717.0
Subtracting 147 from 158 leaves us with 11.
Bring next digit (6) of the dividend behind the 11 and repeat the process: 116 / 21

On to step 6:
21 goes into 116 5 times with a remainder of 11.
Use 5 as the next digit of our solution. 
Result so far: 17175.0
If we take 105 away from 116, we end up 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.

Going ahead to step 7:
If we divide 110 by 21, we get 5 and a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 17175.5
Deduct 105 from 110 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 8:
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: 17175.52
If we subtract 42 from 50, we 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 9:
80 divided by 21 is 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 17175.523
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.

Advancing to step 10:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 17175.5238
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 11:
The number 21 fits into 20 0 times, leaving a remainder of 20.
The next digit of our result is 0. 
Result so far: 17175.5238
The remainder is 20 after subtracting 0 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 12:
The number 21 fits into 200 9 times, leaving a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 17175.523809
Subtract 189 from 200 to 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.

Step 13:
When dividing 110 by 21, we get 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 17175.5238095
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.

Advancing to step 14:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 17175.52380952
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.

The final result is 17175.52380952 with a remainder of 8e-09.