We look at the division of 99709 by 21 
We want to figure out the number of times 99709 can be divided by 21.

Let's proceed to step 1:
21 goes into 9 0 times with a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Fetch the next digit (9) from the dividend, attach it to 9 and continue: 99 / 21

Going ahead to step 2:
When dividing 99 by 21, we get 4 with a remainder of 15.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtracting 84 from 99 leaves us with 15.
Append the next digit (7) from the dividend to 15 and continue with: 157 / 21

On to step 3:
When dividing 157 by 21, we get 7 with a remainder of 10.
The number 7 becomes the next digit in our result. 
Result so far: 47.0
The remainder is 10 after subtracting 147 from 157.
Fetch the next digit (0) from the dividend, attach it to 10 and continue: 100 / 21

Step 4:
21 goes into 100 4 times with a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 474.0
The remainder is 16 after subtracting 84 from 100.
Include the next digit (9) from the dividend after 16, then repeat: 169 / 21

On to step 5:
If we divide 169 by 21, we get 8 and a remainder of 1.
Use 8 as the next digit of our solution. 
Result so far: 4748.0
If we subtract 168 from 169, we 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.

Going ahead to step 6:
21 goes into 10 0 times with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 4748.0
Subtract 0 from 10 to 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.

Moving on to step 7:
21 goes into 100 4 times with a remainder of 16.
The next digit of our result is 4. 
Result so far: 4748.04
Deduct 84 from 100 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 8:
If we divide 160 by 21, we get 7 and a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 4748.047
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 9:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 4748.0476
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 10:
When dividing 40 by 21, we get 1 with a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 4748.04761
If we subtract 21 from 40, we 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.

On to step 11:
21 goes into 190 9 times with a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 4748.047619
Subtracting 189 from 190 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 12:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 4748.047619
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.

Going ahead to step 13:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 4748.04761904
If we take 84 away from 100, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

In conclusion, the division gives 4748.04761904 with a balance of 1.6e-08.