12394678 divided by 309 
Let's see how many times 309 fits into 12394678.

Step 1:
If we divide 1 by 309, we get 0 and a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 309

On to step 2:
309 can be fit into 12 0 times, resulting in a remainder of 12.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 12, we end up with 12.
Grab the next digit (3) from the dividend, add it to 12, then carry on: 123 / 309

Step 3:
When dividing 123 by 309, we get 0 with a remainder of 123.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 123 to get 123.
Append the next digit (9) from the dividend to 123 and continue with: 1239 / 309

Going ahead to step 4:
309 goes into 1239 4 times with a remainder of 3.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we take 1236 away from 1239, we end up with 3.
Take the next digit (4) from the dividend and append it to 3, then repeat: 34 / 309

Going ahead to step 5:
309 can be fit into 34 0 times, resulting in a remainder of 34.
Use 0 as the next digit of our solution. 
Result so far: 40.0
If we take 0 away from 34, we end up with 34.
Append the next digit (6) from the dividend to 34 and continue with: 346 / 309

Advancing to step 6:
The number 309 fits into 346 1 times, leaving a remainder of 37.
The number 1 becomes the next digit in our result. 
Result so far: 401.0
The remainder is 37 after subtracting 309 from 346.
Bring next digit (7) of the dividend behind the 37 and repeat the process: 377 / 309

Going ahead to step 7:
If we divide 377 by 309, we get 1 and a remainder of 68.
Use 1 as the next digit of our solution. 
Result so far: 4011.0
Deduct 309 from 377 and we're left with 68.
Append the next digit (8) from the dividend to 68 and continue with: 688 / 309

Going ahead to step 8:
688 divided by 309 is 2 with a remainder of 70.
The number 2 becomes the next digit in our result. 
Result so far: 40112.0
Deduct 618 from 688 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.

On to step 9:
309 can be fit into 700 2 times, resulting in a remainder of 82.
Write down 2 as next digit of the result. 
Result so far: 40112.2
If we subtract 618 from 700, we get 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

Advancing to step 10:
If we divide 820 by 309, we get 2 and a remainder of 202.
The next digit of our result is 2. 
Result so far: 40112.22
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.

Our division results in 40112.22 with a remaining 0.202.