We're dividing 21057 by 18 
Our goal is to divide 21057 by 18.

Going ahead to step 1:
If we divide 2 by 18, we get 0 and a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 18

Going ahead to step 2:
When dividing 21 by 18, we get 1 with a remainder of 3.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 18 from 21 leaves us with 3.
Grab the next digit (0) from the dividend, add it to 3, then carry on: 30 / 18

On to step 3:
When dividing 30 by 18, we get 1 with a remainder of 12.
Write down 1 as next digit of the result. 
Result so far: 11.0
Subtract 18 from 30 to get 12.
Bring next digit (5) of the dividend behind the 12 and repeat the process: 125 / 18

Let's proceed to step 4:
18 goes into 125 6 times with a remainder of 17.
Put 6 as the next digit of the answer. 
Result so far: 116.0
Deduct 108 from 125 and we're left with 17.
Bring next digit (7) of the dividend behind the 17 and repeat the process: 177 / 18

Step 5:
When dividing 177 by 18, we get 9 with a remainder of 15.
The number 9 becomes the next digit in our result. 
Result so far: 1169.0
Subtract 162 from 177 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.

Going ahead to step 6:
The number 18 fits into 150 8 times, leaving a remainder of 6.
Record the quotient 8 as the next digit in the result. 
Result so far: 1169.8
Subtract 144 from 150 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.

Moving on to step 7:
60 divided by 18 is 3 with a remainder of 6.
Use 3 as the next digit of our solution. 
Result so far: 1169.83
Subtracting 54 from 60 leaves us 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.

Step 8:
60 divided by 18 is 3 with a remainder of 6.
The next digit of our result is 3. 
Result so far: 1169.833
Subtract 54 from 60 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.

Our division results in 1169.833 with a remaining 0.0006.