312459 ÷ 84 
Let's see how many times 84 fits into 312459.

Let's proceed to step 1:
If we divide 3 by 84, we get 0 and a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 84

Going ahead to step 2:
If we divide 31 by 84, we get 0 and a remainder of 31.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 31, we get 31.
Bring next digit (2) of the dividend behind the 31 and repeat the process: 312 / 84

On to step 3:
When dividing 312 by 84, we get 3 with a remainder of 60.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 252 from 312 and we're left with 60.
Fetch the next digit (4) from the dividend, attach it to 60 and continue: 604 / 84

Going ahead to step 4:
84 goes into 604 7 times with a remainder of 16.
The number 7 becomes the next digit in our result. 
Result so far: 37.0
The remainder is 16 after subtracting 588 from 604.
Grab the next digit (5) from the dividend, add it to 16, then carry on: 165 / 84

Advancing to step 5:
165 divided by 84 is 1 with a remainder of 81.
Write down 1 as next digit of the result. 
Result so far: 371.0
The remainder is 81 after subtracting 84 from 165.
Take the next digit (9) from the dividend and append it to 81, then repeat: 819 / 84

On to step 6:
If we divide 819 by 84, we get 9 and a remainder of 63.
Use 9 as the next digit of our solution. 
Result so far: 3719.0
Subtracting 756 from 819 leaves us with 63.
Since there are no more digits in the dividend, we add a zero to the remainder making it 630, and continue the process.

Let's proceed to step 7:
If we divide 630 by 84, we get 7 and a remainder of 42.
Put 7 as the next digit of the answer. 
Result so far: 3719.7
If we take 588 away from 630, we end up 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.

On to step 8:
When dividing 420 by 84, we get 5 with a remainder of 0.
Record the quotient 5 as the next digit in the result. 
Result so far: 3719.75
If we subtract 420 from 420, we 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.

Let's proceed to step 9:
When dividing 0 by 84, we get 0 with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 3719.75
Deduct 0 from 0 and we're left 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.

Advancing to step 10:
84 can be fit into 0 0 times, resulting in a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 3719.75
Deduct 0 from 0 and we're left 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.

The final outcome is 3719.75, with a leftover of 0.0.