We look at the division of 359145 by 21 
Let's see how many times 21 fits into 359145.

On to step 1:
If we divide 3 by 21, we get 0 and a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Take the next digit (5) from the dividend and append it to 3, then repeat: 35 / 21

Step 2:
The number 21 fits into 35 1 times, leaving a remainder of 14.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 14 after subtracting 21 from 35.
Append the next digit (9) from the dividend to 14 and continue with: 149 / 21

Let's proceed to step 3:
21 can be fit into 149 7 times, resulting in a remainder of 2.
Write down 7 as next digit of the result. 
Result so far: 17.0
The remainder is 2 after subtracting 147 from 149.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 21

Advancing to step 4:
If we divide 21 by 21, we get 1 and a remainder of 0.
Use 1 as the next digit of our solution. 
Result so far: 171.0
The remainder is 0 after subtracting 21 from 21.
Include the next digit (4) from the dividend after 0, then repeat: 4 / 21

Advancing to step 5:
The number 21 fits into 4 0 times, leaving a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 1710.0
Subtract 0 from 4 to get 4.
Take the next digit (5) from the dividend and append it to 4, then repeat: 45 / 21

Step 6:
The number 21 fits into 45 2 times, leaving a remainder of 3.
The number 2 becomes the next digit in our result. 
Result so far: 17102.0
The remainder is 3 after subtracting 42 from 45.
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 7:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 17102.1
Subtracting 21 from 30 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.

Advancing to step 8:
90 divided by 21 is 4 with a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 17102.14
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 9:
When dividing 60 by 21, we get 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 17102.142
Subtract 42 from 60 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Step 10:
When dividing 180 by 21, we get 8 with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 17102.1428
Deduct 168 from 180 and we're left 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.

Step 11:
If we divide 120 by 21, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 17102.14285
Subtract 105 from 120 to get 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 12:
150 divided by 21 is 7 with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 17102.142857
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 13:
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: 17102.1428571
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.

On to step 14:
21 goes into 90 4 times with a remainder of 6.
The next digit of our result is 4. 
Result so far: 17102.14285714
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

In conclusion, the division gives 17102.14285714 with a balance of 6e-09.