Let's divide 39405751 by 309
Our goal is to divide 39405751 by 309.

On to step 1:
When dividing 3 by 309, we get 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 309

Moving on to step 2:
309 goes into 39 0 times with a remainder of 39.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 39 and we're left with 39.
Bring next digit (4) of the dividend behind the 39 and repeat the process: 394 / 309

Moving on to step 3:
If we divide 394 by 309, we get 1 and a remainder of 85.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 309 from 394 leaves us with 85.
Append the next digit (0) from the dividend to 85 and continue with: 850 / 309

Step 4:
When dividing 850 by 309, we get 2 with a remainder of 232.
Record the quotient 2 as the next digit in the result. 
Result so far: 12.0
Deduct 618 from 850 and we're left with 232.
Include the next digit (5) from the dividend after 232, then repeat: 2325 / 309

On to step 5:
2325 divided by 309 is 7 with a remainder of 162.
The number 7 becomes the next digit in our result. 
Result so far: 127.0
The remainder is 162 after subtracting 2163 from 2325.
Fetch the next digit (7) from the dividend, attach it to 162 and continue: 1627 / 309

On to step 6:
When dividing 1627 by 309, we get 5 with a remainder of 82.
Record the quotient 5 as the next digit in the result. 
Result so far: 1275.0
The remainder is 82 after subtracting 1545 from 1627.
Append the next digit (5) from the dividend to 82 and continue with: 825 / 309

Going ahead to step 7:
309 goes into 825 2 times with a remainder of 207.
The number 2 becomes the next digit in our result. 
Result so far: 12752.0
Subtract 618 from 825 to get 207.
Include the next digit (1) from the dividend after 207, then repeat: 2071 / 309

Going ahead to step 8:
If we divide 2071 by 309, we get 6 and a remainder of 217.
Record the quotient 6 as the next digit in the result. 
Result so far: 127526.0
The remainder is 217 after subtracting 1854 from 2071.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2170, and continue the process.

Moving on to step 9:
309 can be fit into 2170 7 times, resulting in a remainder of 7.
The next digit of our result is 7. 
Result so far: 127526.7
If we take 2163 away from 2170, we end up with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Going ahead to step 10:
When dividing 70 by 309, we get 0 with a remainder of 70.
The number 0 becomes the next digit in our result. 
Result so far: 127526.7
Deduct 0 from 70 and we're left with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Advancing to step 11:
The number 309 fits into 700 2 times, leaving a remainder of 82.
Put 2 as the next digit of the answer. 
Result so far: 127526.702
Subtracting 618 from 700 leaves us with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

Step 12:
If we divide 820 by 309, we get 2 and a remainder of 202.
Put 2 as the next digit of the answer. 
Result so far: 127526.7022
Subtracting 618 from 820 leaves us with 202.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2020, and continue the process.

The final result is 127526.7022 with a remainder of 0.00202.