We're dividing 15399 by 14 
We're looking to find how many times 14 goes into 15399.

Advancing to step 1:
14 can be fit into 1 0 times, resulting in a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 14

Going ahead to step 2:
14 goes into 15 1 times with a remainder of 1.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 14 from 15 to get 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 14

Step 3:
If we divide 13 by 14, we get 0 and a remainder of 13.
The next digit of our result is 0. 
Result so far: 10.0
If we subtract 0 from 13, we get 13.
Include the next digit (9) from the dividend after 13, then repeat: 139 / 14

Let's proceed to step 4:
139 divided by 14 is 9 with a remainder of 13.
Write down 9 as next digit of the result. 
Result so far: 109.0
The remainder is 13 after subtracting 126 from 139.
Bring next digit (9) of the dividend behind the 13 and repeat the process: 139 / 14

Moving on to step 5:
139 divided by 14 is 9 with a remainder of 13.
Use 9 as the next digit of our solution. 
Result so far: 1099.0
If we subtract 126 from 139, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 6:
130 divided by 14 is 9 with a remainder of 4.
Use 9 as the next digit of our solution. 
Result so far: 1099.9
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 7:
14 goes into 40 2 times with a remainder of 12.
Put 2 as the next digit of the answer. 
Result so far: 1099.92
The remainder is 12 after subtracting 28 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 8:
14 can be fit into 120 8 times, resulting in a remainder of 8.
Write down 8 as next digit of the result. 
Result so far: 1099.928
Deduct 112 from 120 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 9:
14 goes into 80 5 times with a remainder of 10.
Put 5 as the next digit of the answer. 
Result so far: 1099.9285
Subtract 70 from 80 to get 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:
When dividing 100 by 14, we get 7 with a remainder of 2.
Use 7 as the next digit of our solution. 
Result so far: 1099.92857
Subtracting 98 from 100 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 11:
14 can be fit into 20 1 times, resulting in a remainder of 6.
The number 1 becomes the next digit in our result. 
Result so far: 1099.928571
Subtracting 14 from 20 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 12:
When dividing 60 by 14, we get 4 with a remainder of 4.
The next digit of our result is 4. 
Result so far: 1099.9285714
Subtracting 56 from 60 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 13:
40 divided by 14 is 2 with a remainder of 12.
Put 2 as the next digit of the answer. 
Result so far: 1099.92857142
Deduct 28 from 40 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final result is 1099.92857142 with a remainder of 1.2e-08.