We look at the division of 769871 by 21 
Let's see how many times 21 fits into 769871.

Let's proceed 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
The remainder is 7 after subtracting 0 from 7.
Take the next digit (6) from the dividend and append it to 7, then repeat: 76 / 21

Step 2:
The number 21 fits into 76 3 times, leaving a remainder of 13.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 13 after subtracting 63 from 76.
Take the next digit (9) from the dividend and append it to 13, then repeat: 139 / 21

Step 3:
If we divide 139 by 21, we get 6 and a remainder of 13.
Record the quotient 6 as the next digit in the result. 
Result so far: 36.0
If we subtract 126 from 139, we get 13.
Include the next digit (8) from the dividend after 13, then repeat: 138 / 21

Step 4:
21 can be fit into 138 6 times, resulting in a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 366.0
If we subtract 126 from 138, we get 12.
Include the next digit (7) from the dividend after 12, then repeat: 127 / 21

Step 5:
When dividing 127 by 21, we get 6 with a remainder of 1.
The number 6 becomes the next digit in our result. 
Result so far: 3666.0
If we subtract 126 from 127, we get 1.
Append the next digit (1) from the dividend to 1 and continue with: 11 / 21

On to step 6:
The number 21 fits into 11 0 times, leaving a remainder of 11.
The number 0 becomes the next digit in our result. 
Result so far: 36660.0
Deduct 0 from 11 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 7:
110 divided by 21 is 5 with a remainder of 5.
The next digit of our result is 5. 
Result so far: 36660.5
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 8:
50 divided by 21 is 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 36660.52
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 9:
21 can be fit into 80 3 times, resulting in a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 36660.523
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 10:
If we divide 170 by 21, we get 8 and a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 36660.5238
Subtract 168 from 170 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Step 11:
The number 21 fits into 20 0 times, leaving a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 36660.5238
If we take 0 away from 20, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 12:
21 can be fit into 200 9 times, resulting in a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 36660.523809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Let's proceed to step 13:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 36660.5238095
The remainder is 5 after subtracting 105 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 14:
50 divided by 21 is 2 with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 36660.52380952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Our division results in 36660.52380952 with a remaining 8e-09.