We're dividing 258765 by 21 
We're looking to find how many times 21 goes into 258765.

Moving on to step 1:
If we divide 2 by 21, we get 0 and a remainder of 2.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Take the next digit (5) from the dividend and append it to 2, then repeat: 25 / 21

Going ahead to step 2:
When dividing 25 by 21, we get 1 with a remainder of 4.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 21 from 25 and we're left with 4.
Fetch the next digit (8) from the dividend, attach it to 4 and continue: 48 / 21

Advancing to step 3:
If we divide 48 by 21, we get 2 and a remainder of 6.
Put 2 as the next digit of the answer. 
Result so far: 12.0
If we subtract 42 from 48, we get 6.
Bring next digit (7) of the dividend behind the 6 and repeat the process: 67 / 21

Going ahead to step 4:
The number 21 fits into 67 3 times, leaving a remainder of 4.
Use 3 as the next digit of our solution. 
Result so far: 123.0
Subtract 63 from 67 to get 4.
Include the next digit (6) from the dividend after 4, then repeat: 46 / 21

Advancing to step 5:
When dividing 46 by 21, we get 2 with a remainder of 4.
Put 2 as the next digit of the answer. 
Result so far: 1232.0
The remainder is 4 after subtracting 42 from 46.
Fetch the next digit (5) from the dividend, attach it to 4 and continue: 45 / 21

Let's proceed to step 6:
The number 21 fits into 45 2 times, leaving a remainder of 3.
Put 2 as the next digit of the answer. 
Result so far: 12322.0
Subtracting 42 from 45 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.

Going ahead to step 7:
21 can be fit into 30 1 times, resulting in a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 12322.1
If we take 21 away from 30, we end up with 9.
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 8:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 12322.14
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 9:
21 can be fit into 60 2 times, resulting in a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 12322.142
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.

Going ahead to step 10:
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: 12322.1428
If we take 168 away from 180, we end up 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.

Let's proceed to step 11:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 12322.14285
If we take 105 away from 120, we end up with 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 12:
When dividing 150 by 21, we get 7 with a remainder of 3.
The next digit of our result is 7. 
Result so far: 12322.142857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 13:
21 goes into 30 1 times with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 12322.1428571
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 14:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 12322.14285714
If we take 84 away from 90, we end up 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.

Our division results in 12322.14285714 with a remaining 6e-09.