We divide 309129 by 10
We want to divide 309129 by 10.

Advancing to step 1:
When dividing 3 by 10, we get 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 10

Step 2:
When dividing 30 by 10, we get 3 with a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Subtracting 30 from 30 leaves us with 0.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 10

Let's proceed to step 3:
9 divided by 10 is 0 with a remainder of 9.
Write down 0 as next digit of the result. 
Result so far: 30.0
Subtract 0 from 9 to get 9.
Bring next digit (1) of the dividend behind the 9 and repeat the process: 91 / 10

Going ahead to step 4:
The number 10 fits into 91 9 times, leaving a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 309.0
Deduct 90 from 91 and we're left with 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 10

Going ahead to step 5:
10 goes into 12 1 times with a remainder of 2.
Record the quotient 1 as the next digit in the result. 
Result so far: 3091.0
The remainder is 2 after subtracting 10 from 12.
Take the next digit (9) from the dividend and append it to 2, then repeat: 29 / 10

Moving on to step 6:
If we divide 29 by 10, we get 2 and a remainder of 9.
Write down 2 as next digit of the result. 
Result so far: 30912.0
Deduct 20 from 29 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 7:
90 divided by 10 is 9 with a remainder of 0.
The next digit of our result is 9. 
Result so far: 30912.9
If we subtract 90 from 90, 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.

Step 8:
When dividing 0 by 10, we get 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 30912.9
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 9:
If we divide 0 by 10, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 30912.9
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.

After the division, we end up with 30912.9 and a remainder of 0.0.