129553 divided by 21 
Our goal is to divide 129553 by 21.

Let's proceed to step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 21

Let's proceed to step 2:
21 can be fit into 12 0 times, resulting in a remainder of 12.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 12 leaves us with 12.
Take the next digit (9) from the dividend and append it to 12, then repeat: 129 / 21

Step 3:
21 can be fit into 129 6 times, resulting in a remainder of 3.
Record the quotient 6 as the next digit in the result. 
Result so far: 6.0
If we subtract 126 from 129, we get 3.
Grab the next digit (5) from the dividend, add it to 3, then carry on: 35 / 21

On to step 4:
21 goes into 35 1 times with a remainder of 14.
Record the quotient 1 as the next digit in the result. 
Result so far: 61.0
Subtract 21 from 35 to get 14.
Include the next digit (5) from the dividend after 14, then repeat: 145 / 21

Advancing to step 5:
If we divide 145 by 21, we get 6 and a remainder of 19.
Put 6 as the next digit of the answer. 
Result so far: 616.0
If we take 126 away from 145, we end up with 19.
Append the next digit (3) from the dividend to 19 and continue with: 193 / 21

On to step 6:
The number 21 fits into 193 9 times, leaving a remainder of 4.
The number 9 becomes the next digit in our result. 
Result so far: 6169.0
The remainder is 4 after subtracting 189 from 193.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 7:
If we divide 40 by 21, we get 1 and a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 6169.1
Subtracting 21 from 40 leaves us 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.

Going ahead to step 8:
21 goes into 190 9 times with a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 6169.19
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.

Step 9:
21 goes into 10 0 times with a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 6169.19
Deduct 0 from 10 and we're left with 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 10:
100 divided by 21 is 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 6169.1904
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.

Advancing to step 11:
160 divided by 21 is 7 with a remainder of 13.
The next digit of our result is 7. 
Result so far: 6169.19047
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.

Moving on to step 12:
21 can be fit into 130 6 times, resulting in a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 6169.190476
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.

Step 13:
21 goes into 40 1 times with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 6169.1904761
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 14:
21 goes into 190 9 times with a remainder of 1.
The next digit of our result is 9. 
Result so far: 6169.19047619
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.

In conclusion, the division gives 6169.19047619 with a balance of 1e-09.