We divide 399657 by 86
We want to divide 399657 by 86.

Advancing to step 1:
3 divided by 86 is 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 3 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 86

Let's proceed to step 2:
If we divide 39 by 86, we get 0 and a remainder of 39.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 39, we end up with 39.
Take the next digit (9) from the dividend and append it to 39, then repeat: 399 / 86

Step 3:
If we divide 399 by 86, we get 4 and a remainder of 55.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Deduct 344 from 399 and we're left with 55.
Include the next digit (6) from the dividend after 55, then repeat: 556 / 86

On to step 4:
The number 86 fits into 556 6 times, leaving a remainder of 40.
The number 6 becomes the next digit in our result. 
Result so far: 46.0
Deduct 516 from 556 and we're left with 40.
Append the next digit (5) from the dividend to 40 and continue with: 405 / 86

Advancing to step 5:
When dividing 405 by 86, we get 4 with a remainder of 61.
Write down 4 as next digit of the result. 
Result so far: 464.0
If we take 344 away from 405, we end up with 61.
Fetch the next digit (7) from the dividend, attach it to 61 and continue: 617 / 86

On to step 6:
If we divide 617 by 86, we get 7 and a remainder of 15.
Use 7 as the next digit of our solution. 
Result so far: 4647.0
Subtracting 602 from 617 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 7:
150 divided by 86 is 1 with a remainder of 64.
The next digit of our result is 1. 
Result so far: 4647.1
Deduct 86 from 150 and we're left with 64.
Since there are no more digits in the dividend, we add a zero to the remainder making it 640, and continue the process.

Going ahead to step 8:
The number 86 fits into 640 7 times, leaving a remainder of 38.
The next digit of our result is 7. 
Result so far: 4647.17
If we take 602 away from 640, we end up with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

On to step 9:
The number 86 fits into 380 4 times, leaving a remainder of 36.
The next digit of our result is 4. 
Result so far: 4647.174
If we take 344 away from 380, we end up with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

On to step 10:
360 divided by 86 is 4 with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 4647.1744
Deduct 344 from 360 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final outcome is 4647.1744, with a leftover of 0.00016.