We're dividing 79129 by 21 
We want to figure out the number of times 79129 can be divided by 21.

Step 1:
21 can be fit into 7 0 times, resulting in a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Fetch the next digit (9) from the dividend, attach it to 7 and continue: 79 / 21

Moving on to step 2:
21 goes into 79 3 times with a remainder of 16.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Deduct 63 from 79 and we're left with 16.
Bring next digit (1) of the dividend behind the 16 and repeat the process: 161 / 21

Moving on to step 3:
If we divide 161 by 21, we get 7 and a remainder of 14.
Record the quotient 7 as the next digit in the result. 
Result so far: 37.0
The remainder is 14 after subtracting 147 from 161.
Include the next digit (2) from the dividend after 14, then repeat: 142 / 21

Going ahead to step 4:
21 goes into 142 6 times with a remainder of 16.
Record the quotient 6 as the next digit in the result. 
Result so far: 376.0
The remainder is 16 after subtracting 126 from 142.
Take the next digit (9) from the dividend and append it to 16, then repeat: 169 / 21

Going ahead to step 5:
When dividing 169 by 21, we get 8 with a remainder of 1.
The next digit of our result is 8. 
Result so far: 3768.0
Subtracting 168 from 169 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.

On to step 6:
The number 21 fits into 10 0 times, leaving a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 3768.0
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:
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: 3768.04
Subtracting 84 from 100 leaves us 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:
21 goes into 160 7 times with a remainder of 13.
The next digit of our result is 7. 
Result so far: 3768.047
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 9:
21 can be fit into 130 6 times, resulting in a remainder of 4.
The next digit of our result is 6. 
Result so far: 3768.0476
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 10:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 3768.04761
Deduct 21 from 40 and we're left 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.

Let's proceed to step 11:
21 can be fit into 190 9 times, resulting in a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 3768.047619
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 12:
21 can be fit into 10 0 times, resulting in a remainder of 10.
The next digit of our result is 0. 
Result so far: 3768.047619
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 13:
100 divided by 21 is 4 with a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 3768.04761904
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.

Our division results in 3768.04761904 with a remaining 1.6e-08.