Let's divide 851073 by 21
Our goal is to divide 851073 by 21.

Step 1:
21 can be fit into 8 0 times, resulting in a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Bring next digit (5) of the dividend behind the 8 and repeat the process: 85 / 21

Advancing to step 2:
21 can be fit into 85 4 times, resulting in a remainder of 1.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Deduct 84 from 85 and we're left with 1.
Append the next digit (1) from the dividend to 1 and continue with: 11 / 21

Let's proceed to step 3:
If we divide 11 by 21, we get 0 and a remainder of 11.
Record the quotient 0 as the next digit in the result. 
Result so far: 40.0
The remainder is 11 after subtracting 0 from 11.
Take the next digit (0) from the dividend and append it to 11, then repeat: 110 / 21

Going ahead to step 4:
If we divide 110 by 21, we get 5 and a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 405.0
If we take 105 away from 110, we end up with 5.
Grab the next digit (7) from the dividend, add it to 5, then carry on: 57 / 21

Let's proceed to step 5:
21 can be fit into 57 2 times, resulting in a remainder of 15.
Use 2 as the next digit of our solution. 
Result so far: 4052.0
Subtracting 42 from 57 leaves us with 15.
Fetch the next digit (3) from the dividend, attach it to 15 and continue: 153 / 21

Let's proceed to step 6:
21 can be fit into 153 7 times, resulting in a remainder of 6.
Record the quotient 7 as the next digit in the result. 
Result so far: 40527.0
If we subtract 147 from 153, we 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.

Advancing to step 7:
21 goes into 60 2 times with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 40527.2
Deduct 42 from 60 and we're left 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 8:
21 can be fit into 180 8 times, resulting in a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 40527.28
If we subtract 168 from 180, we 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.

Let's proceed to step 9:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 40527.285
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 10:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 40527.2857
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 11:
If we divide 30 by 21, we get 1 and a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 40527.28571
The remainder is 9 after subtracting 21 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 40527.285714
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 13:
60 divided by 21 is 2 with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 40527.2857142
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.

Let's proceed to step 14:
When dividing 180 by 21, we get 8 with a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 40527.28571428
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.

Our division results in 40527.28571428 with a remaining 1.2e-08.