781863 ÷ 21 
We want to divide 781863 by 21.

On to step 1:
If we divide 7 by 21, we get 0 and a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 21

Going ahead to step 2:
21 can be fit into 78 3 times, resulting in a remainder of 15.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 63 from 78 and we're left with 15.
Include the next digit (1) from the dividend after 15, then repeat: 151 / 21

Moving on to step 3:
When dividing 151 by 21, we get 7 with a remainder of 4.
Write down 7 as next digit of the result. 
Result so far: 37.0
Subtracting 147 from 151 leaves us with 4.
Take the next digit (8) from the dividend and append it to 4, then repeat: 48 / 21

Moving on to step 4:
If we divide 48 by 21, we get 2 and a remainder of 6.
Use 2 as the next digit of our solution. 
Result so far: 372.0
If we take 42 away from 48, we end up with 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 21

Going ahead to step 5:
The number 21 fits into 66 3 times, leaving a remainder of 3.
Write down 3 as next digit of the result. 
Result so far: 3723.0
Subtracting 63 from 66 leaves us with 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 21

Moving on to step 6:
33 divided by 21 is 1 with a remainder of 12.
Use 1 as the next digit of our solution. 
Result so far: 37231.0
Subtracting 21 from 33 leaves us 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.

Moving on to step 7:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 37231.5
If we subtract 105 from 120, we 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.

Advancing to step 8:
When dividing 150 by 21, we get 7 with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 37231.57
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.

Step 9:
30 divided by 21 is 1 with a remainder of 9.
The next digit of our result is 1. 
Result so far: 37231.571
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.

Advancing to step 10:
21 goes into 90 4 times with a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 37231.5714
If we subtract 84 from 90, 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.

On to step 11:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 37231.57142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 12:
21 goes into 180 8 times with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 37231.571428
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.

Moving on to step 13:
When dividing 120 by 21, we get 5 with a remainder of 15.
The next digit of our result is 5. 
Result so far: 37231.5714285
If we subtract 105 from 120, we 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.

Moving on to step 14:
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: 37231.57142857
Subtracting 147 from 150 leaves us 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.

The final result is 37231.57142857 with a remainder of 3e-09.