781939 divided by 21 
Our goal is to divide 781939 by 21.

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

Step 2:
21 goes into 78 3 times with a remainder of 15.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we subtract 63 from 78, we get 15.
Grab the next digit (1) from the dividend, add it to 15, then carry on: 151 / 21

On to step 3:
151 divided by 21 is 7 with a remainder of 4.
Write down 7 as next digit of the result. 
Result so far: 37.0
If we take 147 away from 151, we end up with 4.
Grab the next digit (9) from the dividend, add it to 4, then carry on: 49 / 21

Moving on to step 4:
21 goes into 49 2 times with a remainder of 7.
The number 2 becomes the next digit in our result. 
Result so far: 372.0
If we subtract 42 from 49, we get 7.
Append the next digit (3) from the dividend to 7 and continue with: 73 / 21

Moving on to step 5:
73 divided by 21 is 3 with a remainder of 10.
Use 3 as the next digit of our solution. 
Result so far: 3723.0
Subtracting 63 from 73 leaves us with 10.
Append the next digit (9) from the dividend to 10 and continue with: 109 / 21

On to step 6:
109 divided by 21 is 5 with a remainder of 4.
The next digit of our result is 5. 
Result so far: 37235.0
Subtracting 105 from 109 leaves us 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 7:
The number 21 fits into 40 1 times, leaving a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 37235.1
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 8:
When dividing 190 by 21, we get 9 with a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 37235.19
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 9:
21 goes into 10 0 times with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 37235.19
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 10:
When dividing 100 by 21, we get 4 with a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 37235.1904
Subtract 84 from 100 to get 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 11:
The number 21 fits into 160 7 times, leaving a remainder of 13.
The next digit of our result is 7. 
Result so far: 37235.19047
Subtracting 147 from 160 leaves us 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.

On to step 12:
21 can be fit into 130 6 times, resulting in a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 37235.190476
Subtract 126 from 130 to get 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 13:
40 divided by 21 is 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 37235.1904761
Subtract 21 from 40 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Step 14:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 37235.19047619
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.

The final outcome is 37235.19047619, with a leftover of 1e-09.