We divide 399387 by 10
We want to figure out the number of times 399387 can be divided by 10.

Going ahead to step 1:
10 goes into 3 0 times with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 10

Let's proceed to step 2:
10 can be fit into 39 3 times, resulting in a remainder of 9.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtracting 30 from 39 leaves us with 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 10

Advancing to step 3:
When dividing 99 by 10, we get 9 with a remainder of 9.
Use 9 as the next digit of our solution. 
Result so far: 39.0
Subtracting 90 from 99 leaves us with 9.
Include the next digit (3) from the dividend after 9, then repeat: 93 / 10

On to step 4:
If we divide 93 by 10, we get 9 and a remainder of 3.
The number 9 becomes the next digit in our result. 
Result so far: 399.0
Subtract 90 from 93 to get 3.
Grab the next digit (8) from the dividend, add it to 3, then carry on: 38 / 10

Advancing to step 5:
10 can be fit into 38 3 times, resulting in a remainder of 8.
Use 3 as the next digit of our solution. 
Result so far: 3993.0
The remainder is 8 after subtracting 30 from 38.
Append the next digit (7) from the dividend to 8 and continue with: 87 / 10

On to step 6:
10 goes into 87 8 times with a remainder of 7.
The next digit of our result is 8. 
Result so far: 39938.0
Deduct 80 from 87 and we're left 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 7:
70 divided by 10 is 7 with a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 39938.7
If we take 70 away from 70, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
The number 10 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 39938.7
Subtract 0 from 0 to 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 9:
When dividing 0 by 10, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 39938.7
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.

The final result is 39938.7 with a remainder of 0.0.