We look at the division of 12799357 by 387 
Our goal is to divide 12799357 by 387.

Advancing to step 1:
The number 387 fits into 1 0 times, leaving a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 387

Let's proceed to step 2:
If we divide 12 by 387, we get 0 and a remainder of 12.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 12 leaves us with 12.
Fetch the next digit (7) from the dividend, attach it to 12 and continue: 127 / 387

Going ahead to step 3:
If we divide 127 by 387, we get 0 and a remainder of 127.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 127 leaves us with 127.
Include the next digit (9) from the dividend after 127, then repeat: 1279 / 387

Going ahead to step 4:
The number 387 fits into 1279 3 times, leaving a remainder of 118.
The next digit of our result is 3. 
Result so far: 3.0
The remainder is 118 after subtracting 1161 from 1279.
Fetch the next digit (9) from the dividend, attach it to 118 and continue: 1189 / 387

On to step 5:
If we divide 1189 by 387, we get 3 and a remainder of 28.
Write down 3 as next digit of the result. 
Result so far: 33.0
If we subtract 1161 from 1189, we get 28.
Take the next digit (3) from the dividend and append it to 28, then repeat: 283 / 387

On to step 6:
387 can be fit into 283 0 times, resulting in a remainder of 283.
Record the quotient 0 as the next digit in the result. 
Result so far: 330.0
Subtract 0 from 283 to get 283.
Include the next digit (5) from the dividend after 283, then repeat: 2835 / 387

Moving on to step 7:
387 can be fit into 2835 7 times, resulting in a remainder of 126.
The next digit of our result is 7. 
Result so far: 3307.0
If we subtract 2709 from 2835, we get 126.
Grab the next digit (7) from the dividend, add it to 126, then carry on: 1267 / 387

Moving on to step 8:
The number 387 fits into 1267 3 times, leaving a remainder of 106.
The number 3 becomes the next digit in our result. 
Result so far: 33073.0
Deduct 1161 from 1267 and we're left with 106.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1060, and continue the process.

Step 9:
387 goes into 1060 2 times with a remainder of 286.
The next digit of our result is 2. 
Result so far: 33073.2
Deduct 774 from 1060 and we're left with 286.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2860, and continue the process.

On to step 10:
387 goes into 2860 7 times with a remainder of 151.
Use 7 as the next digit of our solution. 
Result so far: 33073.27
Subtract 2709 from 2860 to get 151.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1510, and continue the process.

Advancing to step 11:
387 can be fit into 1510 3 times, resulting in a remainder of 349.
Record the quotient 3 as the next digit in the result. 
Result so far: 33073.273
Subtract 1161 from 1510 to get 349.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3490, and continue the process.

On to step 12:
3490 divided by 387 is 9 with a remainder of 7.
The number 9 becomes the next digit in our result. 
Result so far: 33073.2739
Subtracting 3483 from 3490 leaves us 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.

On to step 13:
When dividing 70 by 387, we get 0 with a remainder of 70.
Put 0 as the next digit of the answer. 
Result so far: 33073.2739
If we take 0 away from 70, we end up 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.

Let's proceed to step 14:
700 divided by 387 is 1 with a remainder of 313.
The number 1 becomes the next digit in our result. 
Result so far: 33073.273901
If we subtract 387 from 700, we get 313.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3130, and continue the process.

Advancing to step 15:
When dividing 3130 by 387, we get 8 with a remainder of 34.
The number 8 becomes the next digit in our result. 
Result so far: 33073.2739018
If we take 3096 away from 3130, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Advancing to step 16:
387 goes into 340 0 times with a remainder of 340.
Use 0 as the next digit of our solution. 
Result so far: 33073.2739018
Subtract 0 from 340 to get 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3400, and continue the process.

The final outcome is 33073.2739018, with a leftover of 3.4e-07.