We're dividing 129720 by 20 
We want to divide 129720 by 20.

On to step 1:
20 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Take the next digit (2) from the dividend and append it to 1, then repeat: 12 / 20

Moving on to step 2:
The number 20 fits into 12 0 times, leaving a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 12 after subtracting 0 from 12.
Bring next digit (9) of the dividend behind the 12 and repeat the process: 129 / 20

Advancing to step 3:
The number 20 fits into 129 6 times, leaving a remainder of 9.
Put 6 as the next digit of the answer. 
Result so far: 6.0
Subtracting 120 from 129 leaves us with 9.
Bring next digit (7) of the dividend behind the 9 and repeat the process: 97 / 20

On to step 4:
The number 20 fits into 97 4 times, leaving a remainder of 17.
The next digit of our result is 4. 
Result so far: 64.0
Subtracting 80 from 97 leaves us with 17.
Take the next digit (2) from the dividend and append it to 17, then repeat: 172 / 20

Step 5:
20 can be fit into 172 8 times, resulting in a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 648.0
If we take 160 away from 172, we end up with 12.
Fetch the next digit (0) from the dividend, attach it to 12 and continue: 120 / 20

Going ahead to step 6:
20 goes into 120 6 times with a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 6486.0
If we subtract 120 from 120, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 7:
20 goes into 0 0 times with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 6486.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 8:
When dividing 0 by 20, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 6486.0
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

In conclusion, the division gives 6486.0 with a balance of 0.0.