We're dividing 871368 by 21 
Let's see how many times 21 fits into 871368.

Advancing to step 1:
21 goes into 8 0 times with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Bring next digit (7) of the dividend behind the 8 and repeat the process: 87 / 21

Let's proceed to step 2:
21 can be fit into 87 4 times, resulting in a remainder of 3.
The next digit of our result is 4. 
Result so far: 4.0
If we subtract 84 from 87, we get 3.
Take the next digit (1) from the dividend and append it to 3, then repeat: 31 / 21

Moving on to step 3:
When dividing 31 by 21, we get 1 with a remainder of 10.
The next digit of our result is 1. 
Result so far: 41.0
The remainder is 10 after subtracting 21 from 31.
Bring next digit (3) of the dividend behind the 10 and repeat the process: 103 / 21

Let's proceed to step 4:
103 divided by 21 is 4 with a remainder of 19.
Record the quotient 4 as the next digit in the result. 
Result so far: 414.0
If we take 84 away from 103, we end up with 19.
Bring next digit (6) of the dividend behind the 19 and repeat the process: 196 / 21

Advancing to step 5:
21 can be fit into 196 9 times, resulting in a remainder of 7.
Record the quotient 9 as the next digit in the result. 
Result so far: 4149.0
The remainder is 7 after subtracting 189 from 196.
Grab the next digit (8) from the dividend, add it to 7, then carry on: 78 / 21

Moving on to step 6:
When dividing 78 by 21, we get 3 with a remainder of 15.
Use 3 as the next digit of our solution. 
Result so far: 41493.0
If we subtract 63 from 78, 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 7:
21 can be fit into 150 7 times, resulting in a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 41493.7
Deduct 147 from 150 and we're left 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 8:
When dividing 30 by 21, we get 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 41493.71
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 9:
If we divide 90 by 21, we get 4 and a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 41493.714
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.

Advancing to step 10:
21 goes into 60 2 times with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 41493.7142
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Step 11:
If we divide 180 by 21, we get 8 and a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 41493.71428
Subtract 168 from 180 to 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:
21 goes into 120 5 times with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 41493.714285
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.

Let's proceed to step 13:
150 divided by 21 is 7 with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 41493.7142857
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 14:
21 goes into 30 1 times with a remainder of 9.
The next digit of our result is 1. 
Result so far: 41493.71428571
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 quotient of the division is 41493.71428571, and the remainder is 9e-09.