We're dividing 312988 by 86 
Let's see how many times 86 fits into 312988.

Advancing to step 1:
When dividing 3 by 86, we get 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Grab the next digit (1) from the dividend, add it to 3, then carry on: 31 / 86

Going ahead to step 2:
86 can be fit into 31 0 times, resulting in a remainder of 31.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 31, we end up with 31.
Append the next digit (2) from the dividend to 31 and continue with: 312 / 86

Going ahead to step 3:
When dividing 312 by 86, we get 3 with a remainder of 54.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 258 from 312 and we're left with 54.
Include the next digit (9) from the dividend after 54, then repeat: 549 / 86

Advancing to step 4:
When dividing 549 by 86, we get 6 with a remainder of 33.
The number 6 becomes the next digit in our result. 
Result so far: 36.0
Subtracting 516 from 549 leaves us with 33.
Include the next digit (8) from the dividend after 33, then repeat: 338 / 86

Step 5:
338 divided by 86 is 3 with a remainder of 80.
The number 3 becomes the next digit in our result. 
Result so far: 363.0
Subtract 258 from 338 to get 80.
Take the next digit (8) from the dividend and append it to 80, then repeat: 808 / 86

Advancing to step 6:
86 can be fit into 808 9 times, resulting in a remainder of 34.
The next digit of our result is 9. 
Result so far: 3639.0
If we take 774 away from 808, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

On to step 7:
340 divided by 86 is 3 with a remainder of 82.
Record the quotient 3 as the next digit in the result. 
Result so far: 3639.3
Subtracting 258 from 340 leaves us with 82.
Since there are no more digits in the dividend, we add a zero to the remainder making it 820, and continue the process.

Moving on to step 8:
820 divided by 86 is 9 with a remainder of 46.
Use 9 as the next digit of our solution. 
Result so far: 3639.39
If we subtract 774 from 820, we get 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

On to step 9:
86 goes into 460 5 times with a remainder of 30.
Write down 5 as next digit of the result. 
Result so far: 3639.395
The remainder is 30 after subtracting 430 from 460.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 10:
When dividing 300 by 86, we get 3 with a remainder of 42.
Write down 3 as next digit of the result. 
Result so far: 3639.3953
Subtract 258 from 300 to get 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Let's proceed to step 11:
If we divide 420 by 86, we get 4 and a remainder of 76.
Write down 4 as next digit of the result. 
Result so far: 3639.39534
The remainder is 76 after subtracting 344 from 420.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Going ahead to step 12:
When dividing 760 by 86, we get 8 with a remainder of 72.
Record the quotient 8 as the next digit in the result. 
Result so far: 3639.395348
Deduct 688 from 760 and we're left with 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

On to step 13:
720 divided by 86 is 8 with a remainder of 32.
The number 8 becomes the next digit in our result. 
Result so far: 3639.3953488
The remainder is 32 after subtracting 688 from 720.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

After the division, we end up with 3639.3953488 and a remainder of 3.2e-07.