We look at the division of 878947 by 21 
Let's see how many times 21 fits into 878947.

On to step 1:
If we divide 8 by 21, we get 0 and a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Grab the next digit (7) from the dividend, add it to 8, then carry on: 87 / 21

Advancing to step 2:
The number 21 fits into 87 4 times, leaving 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.
Append the next digit (8) from the dividend to 3 and continue with: 38 / 21

Moving on to step 3:
21 goes into 38 1 times with a remainder of 17.
Record the quotient 1 as the next digit in the result. 
Result so far: 41.0
Subtract 21 from 38 to get 17.
Fetch the next digit (9) from the dividend, attach it to 17 and continue: 179 / 21

Let's proceed to step 4:
The number 21 fits into 179 8 times, leaving a remainder of 11.
Use 8 as the next digit of our solution. 
Result so far: 418.0
Deduct 168 from 179 and we're left with 11.
Fetch the next digit (4) from the dividend, attach it to 11 and continue: 114 / 21

Let's proceed to step 5:
The number 21 fits into 114 5 times, leaving a remainder of 9.
Record the quotient 5 as the next digit in the result. 
Result so far: 4185.0
Subtracting 105 from 114 leaves us with 9.
Include the next digit (7) from the dividend after 9, then repeat: 97 / 21

On to step 6:
When dividing 97 by 21, we get 4 with a remainder of 13.
The number 4 becomes the next digit in our result. 
Result so far: 41854.0
Subtract 84 from 97 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 7:
If we divide 130 by 21, we get 6 and a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 41854.6
Subtracting 126 from 130 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 8:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 41854.61
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.

Going ahead to step 9:
When dividing 190 by 21, we get 9 with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 41854.619
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.

Let's proceed to step 10:
When dividing 10 by 21, we get 0 with a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 41854.619
If we subtract 0 from 10, we get 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 11:
When dividing 100 by 21, we get 4 with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 41854.61904
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.

Step 12:
21 goes into 160 7 times with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 41854.619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 13:
21 goes into 130 6 times with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 41854.6190476
Deduct 126 from 130 and we're left 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 14:
21 can be fit into 40 1 times, resulting in a remainder of 19.
The next digit of our result is 1. 
Result so far: 41854.61904761
If we take 21 away from 40, we end up 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.

Our division results in 41854.61904761 with a remaining 1.9e-08.