We look at the division of 270993 by 21 
Let's see how many times 21 fits into 270993.

Step 1:
21 can be fit into 2 0 times, resulting in a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Fetch the next digit (7) from the dividend, attach it to 2 and continue: 27 / 21

On to step 2:
If we divide 27 by 21, we get 1 and a remainder of 6.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtract 21 from 27 to get 6.
Append the next digit (0) from the dividend to 6 and continue with: 60 / 21

Going ahead to step 3:
21 goes into 60 2 times with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 12.0
Subtracting 42 from 60 leaves us with 18.
Take the next digit (9) from the dividend and append it to 18, then repeat: 189 / 21

Advancing to step 4:
If we divide 189 by 21, we get 9 and a remainder of 0.
The next digit of our result is 9. 
Result so far: 129.0
Deduct 189 from 189 and we're left with 0.
Grab the next digit (9) from the dividend, add it to 0, then carry on: 9 / 21

Step 5:
21 goes into 9 0 times with a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 1290.0
The remainder is 9 after subtracting 0 from 9.
Include the next digit (3) from the dividend after 9, then repeat: 93 / 21

Advancing to step 6:
93 divided by 21 is 4 with a remainder of 9.
The number 4 becomes the next digit in our result. 
Result so far: 12904.0
If we subtract 84 from 93, we get 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 7:
When dividing 90 by 21, we get 4 with a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 12904.4
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.

Let's proceed to step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 12904.42
If we take 42 away from 60, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 9:
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: 12904.428
Subtract 168 from 180 to 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.

On to step 10:
21 goes into 120 5 times with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 12904.4285
Deduct 105 from 120 and we're left 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.

Advancing to step 11:
The number 21 fits into 150 7 times, leaving a remainder of 3.
The next digit of our result is 7. 
Result so far: 12904.42857
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.

Moving on to step 12:
When dividing 30 by 21, we get 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 12904.428571
If we subtract 21 from 30, we get 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 13:
If we divide 90 by 21, we get 4 and a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 12904.4285714
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.

Advancing to step 14:
21 can be fit into 60 2 times, resulting in a remainder of 18.
The next digit of our result is 2. 
Result so far: 12904.42857142
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.

After the division, we end up with 12904.42857142 and a remainder of 1.8e-08.