We look at the division of 489086 by 21 
We want to figure out the number of times 489086 can be divided by 21.

Step 1:
4 divided by 21 is 0 with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Include the next digit (8) from the dividend after 4, then repeat: 48 / 21

Going ahead to step 2:
The number 21 fits into 48 2 times, leaving a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
The remainder is 6 after subtracting 42 from 48.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 21

Going ahead to step 3:
21 can be fit into 69 3 times, resulting in a remainder of 6.
Write down 3 as next digit of the result. 
Result so far: 23.0
Subtracting 63 from 69 leaves us with 6.
Take the next digit (0) from the dividend and append it to 6, then repeat: 60 / 21

Moving on to step 4:
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: 232.0
If we take 42 away from 60, we end up with 18.
Grab the next digit (8) from the dividend, add it to 18, then carry on: 188 / 21

Let's proceed to step 5:
21 can be fit into 188 8 times, resulting in a remainder of 20.
Write down 8 as next digit of the result. 
Result so far: 2328.0
Subtract 168 from 188 to get 20.
Fetch the next digit (6) from the dividend, attach it to 20 and continue: 206 / 21

Going ahead to step 6:
When dividing 206 by 21, we get 9 with a remainder of 17.
Record the quotient 9 as the next digit in the result. 
Result so far: 23289.0
Deduct 189 from 206 and we're left 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.

Let's proceed to step 7:
170 divided by 21 is 8 with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 23289.8
Subtracting 168 from 170 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 8:
21 goes into 20 0 times with a remainder of 20.
The next digit of our result is 0. 
Result so far: 23289.8
Subtract 0 from 20 to get 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 9:
200 divided by 21 is 9 with a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 23289.809
Subtract 189 from 200 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 10:
110 divided by 21 is 5 with a remainder of 5.
The next digit of our result is 5. 
Result so far: 23289.8095
Deduct 105 from 110 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 11:
If we divide 50 by 21, we get 2 and a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 23289.80952
Deduct 42 from 50 and we're left 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 12:
80 divided by 21 is 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 23289.809523
Subtract 63 from 80 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 13:
170 divided by 21 is 8 with a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 23289.8095238
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 14:
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: 23289.8095238
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Our division results in 23289.8095238 with a remaining 2e-08.