287127 divided by 21 
We want to figure out the number of times 287127 can be divided by 21.

Let's proceed to step 1:
The number 21 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Include the next digit (8) from the dividend after 2, then repeat: 28 / 21

Moving on to step 2:
28 divided by 21 is 1 with a remainder of 7.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 21 from 28 and we're left with 7.
Fetch the next digit (7) from the dividend, attach it to 7 and continue: 77 / 21

Moving on to step 3:
When dividing 77 by 21, we get 3 with a remainder of 14.
Write down 3 as next digit of the result. 
Result so far: 13.0
The remainder is 14 after subtracting 63 from 77.
Append the next digit (1) from the dividend to 14 and continue with: 141 / 21

Moving on to step 4:
The number 21 fits into 141 6 times, leaving a remainder of 15.
The number 6 becomes the next digit in our result. 
Result so far: 136.0
Subtract 126 from 141 to get 15.
Bring next digit (2) of the dividend behind the 15 and repeat the process: 152 / 21

Going ahead to step 5:
The number 21 fits into 152 7 times, leaving a remainder of 5.
The next digit of our result is 7. 
Result so far: 1367.0
If we take 147 away from 152, we end up with 5.
Bring next digit (7) of the dividend behind the 5 and repeat the process: 57 / 21

Moving on to step 6:
The number 21 fits into 57 2 times, leaving a remainder of 15.
Record the quotient 2 as the next digit in the result. 
Result so far: 13672.0
If we subtract 42 from 57, 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.

On to step 7:
21 goes into 150 7 times with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 13672.7
If we subtract 147 from 150, we 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.

Advancing to step 8:
30 divided by 21 is 1 with a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 13672.71
Subtracting 21 from 30 leaves us 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 9:
The number 21 fits into 90 4 times, leaving a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 13672.714
Subtract 84 from 90 to 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.

Let's proceed to step 10:
21 goes into 60 2 times with a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 13672.7142
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.

Moving on to step 11:
The number 21 fits into 180 8 times, leaving a remainder of 12.
The next digit of our result is 8. 
Result so far: 13672.71428
If we subtract 168 from 180, we get 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 12:
120 divided by 21 is 5 with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 13672.714285
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.

Moving on to step 13:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 13672.7142857
If we take 147 away from 150, we end up 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 14:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 13672.71428571
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.

The final outcome is 13672.71428571, with a leftover of 9e-09.