We're dividing 359996 by 21 
We're looking to find how many times 21 goes into 359996.

Advancing to step 1:
21 goes into 3 0 times with a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Append the next digit (5) from the dividend to 3 and continue with: 35 / 21

Step 2:
If we divide 35 by 21, we get 1 and 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.
Fetch the next digit (9) from the dividend, attach it to 14 and continue: 149 / 21

Moving on to step 3:
When dividing 149 by 21, we get 7 with a remainder of 2.
Put 7 as the next digit of the answer. 
Result so far: 17.0
The remainder is 2 after subtracting 147 from 149.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 21

Advancing to step 4:
29 divided by 21 is 1 with a remainder of 8.
Put 1 as the next digit of the answer. 
Result so far: 171.0
Deduct 21 from 29 and we're left with 8.
Bring next digit (9) of the dividend behind the 8 and repeat the process: 89 / 21

Moving on to step 5:
89 divided by 21 is 4 with a remainder of 5.
Use 4 as the next digit of our solution. 
Result so far: 1714.0
Subtracting 84 from 89 leaves us with 5.
Bring next digit (6) of the dividend behind the 5 and repeat the process: 56 / 21

Advancing to step 6:
21 goes into 56 2 times with a remainder of 14.
The next digit of our result is 2. 
Result so far: 17142.0
If we subtract 42 from 56, we get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Advancing to step 7:
21 can be fit into 140 6 times, resulting in a remainder of 14.
Put 6 as the next digit of the answer. 
Result so far: 17142.6
If we take 126 away from 140, we end up with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Moving on to step 8:
The number 21 fits into 140 6 times, leaving a remainder of 14.
Record the quotient 6 as the next digit in the result. 
Result so far: 17142.66
Deduct 126 from 140 and we're left with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

The final outcome is 17142.66, with a leftover of 0.014.