Let's divide 851251 by 21
Our goal is to divide 851251 by 21.

Going ahead to step 1:
The number 21 fits into 8 0 times, leaving 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

Let's proceed to step 2:
21 can be fit into 85 4 times, resulting in a remainder of 1.
The next digit of our result is 4. 
Result so far: 4.0
Subtract 84 from 85 to get 1.
Fetch the next digit (1) from the dividend, attach it to 1 and continue: 11 / 21

Going ahead to step 3:
21 can be fit into 11 0 times, resulting in a remainder of 11.
Write down 0 as next digit of the result. 
Result so far: 40.0
Deduct 0 from 11 and we're left with 11.
Append the next digit (2) from the dividend to 11 and continue with: 112 / 21

Advancing to step 4:
If we divide 112 by 21, we get 5 and a remainder of 7.
Use 5 as the next digit of our solution. 
Result so far: 405.0
Deduct 105 from 112 and we're left with 7.
Grab the next digit (5) from the dividend, add it to 7, then carry on: 75 / 21

Step 5:
When dividing 75 by 21, we get 3 with a remainder of 12.
The number 3 becomes the next digit in our result. 
Result so far: 4053.0
Subtract 63 from 75 to get 12.
Append the next digit (1) from the dividend to 12 and continue with: 121 / 21

Going ahead to step 6:
When dividing 121 by 21, we get 5 with a remainder of 16.
Write down 5 as next digit of the result. 
Result so far: 40535.0
Subtracting 105 from 121 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 7:
When dividing 160 by 21, we get 7 with a remainder of 13.
The next digit of our result is 7. 
Result so far: 40535.7
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 8:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 40535.76
If we take 126 away from 130, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 9:
40 divided by 21 is 1 with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 40535.761
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 10:
21 goes into 190 9 times with a remainder of 1.
The next digit of our result is 9. 
Result so far: 40535.7619
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 11:
When dividing 10 by 21, we get 0 with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 40535.7619
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 12:
When dividing 100 by 21, we get 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 40535.761904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 13:
21 goes into 160 7 times with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 40535.7619047
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 14:
21 can be fit into 130 6 times, resulting in a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 40535.76190476
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Our division results in 40535.76190476 with a remaining 4e-09.