399986 ÷ 15 
We want to divide 399986 by 15.

Going ahead to step 1:
15 can be fit into 3 0 times, resulting in a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 15

On to step 2:
39 divided by 15 is 2 with a remainder of 9.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Subtracting 30 from 39 leaves us with 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 15

Going ahead to step 3:
The number 15 fits into 99 6 times, leaving a remainder of 9.
Record the quotient 6 as the next digit in the result. 
Result so far: 26.0
Deduct 90 from 99 and we're left with 9.
Bring next digit (9) of the dividend behind the 9 and repeat the process: 99 / 15

Step 4:
The number 15 fits into 99 6 times, leaving a remainder of 9.
Write down 6 as next digit of the result. 
Result so far: 266.0
If we take 90 away from 99, we end up with 9.
Include the next digit (8) from the dividend after 9, then repeat: 98 / 15

Going ahead to step 5:
If we divide 98 by 15, we get 6 and a remainder of 8.
The number 6 becomes the next digit in our result. 
Result so far: 2666.0
Subtracting 90 from 98 leaves us with 8.
Include the next digit (6) from the dividend after 8, then repeat: 86 / 15

Let's proceed to step 6:
86 divided by 15 is 5 with a remainder of 11.
Record the quotient 5 as the next digit in the result. 
Result so far: 26665.0
Subtract 75 from 86 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Let's proceed to step 7:
15 goes into 110 7 times with a remainder of 5.
Record the quotient 7 as the next digit in the result. 
Result so far: 26665.7
Subtract 105 from 110 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 8:
15 goes into 50 3 times with a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 26665.73
The remainder is 5 after subtracting 45 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 9:
15 goes into 50 3 times with a remainder of 5.
Put 3 as the next digit of the answer. 
Result so far: 26665.733
If we subtract 45 from 50, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

After the division, we end up with 26665.733 and a remainder of 0.0005.