We're dividing 399363 by 16 
We want to figure out the number of times 399363 can be divided by 16.

Advancing to step 1:
If we divide 3 by 16, we get 0 and a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 16

Going ahead to step 2:
16 can be fit into 39 2 times, resulting in a remainder of 7.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtracting 32 from 39 leaves us with 7.
Fetch the next digit (9) from the dividend, attach it to 7 and continue: 79 / 16

Advancing to step 3:
79 divided by 16 is 4 with a remainder of 15.
Use 4 as the next digit of our solution. 
Result so far: 24.0
Subtracting 64 from 79 leaves us with 15.
Include the next digit (3) from the dividend after 15, then repeat: 153 / 16

Advancing to step 4:
When dividing 153 by 16, we get 9 with a remainder of 9.
Record the quotient 9 as the next digit in the result. 
Result so far: 249.0
Subtracting 144 from 153 leaves us with 9.
Fetch the next digit (6) from the dividend, attach it to 9 and continue: 96 / 16

Moving on to step 5:
When dividing 96 by 16, we get 6 with a remainder of 0.
Use 6 as the next digit of our solution. 
Result so far: 2496.0
Subtracting 96 from 96 leaves us with 0.
Take the next digit (3) from the dividend and append it to 0, then repeat: 3 / 16

Going ahead to step 6:
If we divide 3 by 16, we get 0 and a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 24960.0
Subtracting 0 from 3 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 7:
When dividing 30 by 16, we get 1 with a remainder of 14.
Use 1 as the next digit of our solution. 
Result so far: 24960.1
If we subtract 16 from 30, we get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 8:
16 can be fit into 140 8 times, resulting in a remainder of 12.
The next digit of our result is 8. 
Result so far: 24960.18
Subtract 128 from 140 to get 12.
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 9:
120 divided by 16 is 7 with a remainder of 8.
The next digit of our result is 7. 
Result so far: 24960.187
The remainder is 8 after subtracting 112 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 10:
80 divided by 16 is 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 24960.1875
If we subtract 80 from 80, 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 11:
0 divided by 16 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 24960.1875
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.

Step 12:
0 divided by 16 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 24960.1875
If we subtract 0 from 0, 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.

The final outcome is 24960.1875, with a leftover of 0.0.