We're dividing 312189 by 87 
We're looking to find how many times 87 goes into 312189.

On to step 1:
If we divide 3 by 87, we get 0 and a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 3 leaves us with 3.
Take the next digit (1) from the dividend and append it to 3, then repeat: 31 / 87

Going ahead to step 2:
87 goes into 31 0 times with a remainder of 31.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 31 after subtracting 0 from 31.
Append the next digit (2) from the dividend to 31 and continue with: 312 / 87

Let's proceed to step 3:
If we divide 312 by 87, we get 3 and a remainder of 51.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 51 after subtracting 261 from 312.
Include the next digit (1) from the dividend after 51, then repeat: 511 / 87

Moving on to step 4:
When dividing 511 by 87, we get 5 with a remainder of 76.
The number 5 becomes the next digit in our result. 
Result so far: 35.0
If we take 435 away from 511, we end up with 76.
Take the next digit (8) from the dividend and append it to 76, then repeat: 768 / 87

Step 5:
87 can be fit into 768 8 times, resulting in a remainder of 72.
Put 8 as the next digit of the answer. 
Result so far: 358.0
Deduct 696 from 768 and we're left with 72.
Fetch the next digit (9) from the dividend, attach it to 72 and continue: 729 / 87

Going ahead to step 6:
The number 87 fits into 729 8 times, leaving a remainder of 33.
The number 8 becomes the next digit in our result. 
Result so far: 3588.0
If we take 696 away from 729, we end up with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Advancing to step 7:
When dividing 330 by 87, we get 3 with a remainder of 69.
The next digit of our result is 3. 
Result so far: 3588.3
Deduct 261 from 330 and we're left with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Let's proceed to step 8:
The number 87 fits into 690 7 times, leaving a remainder of 81.
Write down 7 as next digit of the result. 
Result so far: 3588.37
Subtracting 609 from 690 leaves us with 81.
Since there are no more digits in the dividend, we add a zero to the remainder making it 810, and continue the process.

Moving on to step 9:
If we divide 810 by 87, we get 9 and a remainder of 27.
Use 9 as the next digit of our solution. 
Result so far: 3588.379
Subtract 783 from 810 to get 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Moving on to step 10:
If we divide 270 by 87, we get 3 and a remainder of 9.
Record the quotient 3 as the next digit in the result. 
Result so far: 3588.3793
The remainder is 9 after subtracting 261 from 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 11:
90 divided by 87 is 1 with a remainder of 3.
The number 1 becomes the next digit in our result. 
Result so far: 3588.37931
If we subtract 87 from 90, we get 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 12:
87 can be fit into 30 0 times, resulting in a remainder of 30.
The next digit of our result is 0. 
Result so far: 3588.37931
If we subtract 0 from 30, we get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Moving on to step 13:
87 goes into 300 3 times with a remainder of 39.
Write down 3 as next digit of the result. 
Result so far: 3588.3793103
If we take 261 away from 300, we end up with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 14:
If we divide 390 by 87, we get 4 and a remainder of 42.
The number 4 becomes the next digit in our result. 
Result so far: 3588.37931034
Subtracting 348 from 390 leaves us with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

The final result is 3588.37931034 with a remainder of 4.2e-08.