We're dividing 315285 by 42 
Let's see how many times 42 fits into 315285.

Step 1:
3 divided by 42 is 0 with a remainder of 3.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Grab the next digit (1) from the dividend, add it to 3, then carry on: 31 / 42

Going ahead to step 2:
When dividing 31 by 42, we get 0 with a remainder of 31.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 31, we get 31.
Bring next digit (5) of the dividend behind the 31 and repeat the process: 315 / 42

Going ahead to step 3:
If we divide 315 by 42, we get 7 and a remainder of 21.
Put 7 as the next digit of the answer. 
Result so far: 7.0
Subtract 294 from 315 to get 21.
Include the next digit (2) from the dividend after 21, then repeat: 212 / 42

On to step 4:
If we divide 212 by 42, we get 5 and a remainder of 2.
Record the quotient 5 as the next digit in the result. 
Result so far: 75.0
If we take 210 away from 212, we end up with 2.
Include the next digit (8) from the dividend after 2, then repeat: 28 / 42

Let's proceed to step 5:
The number 42 fits into 28 0 times, leaving a remainder of 28.
Write down 0 as next digit of the result. 
Result so far: 750.0
The remainder is 28 after subtracting 0 from 28.
Fetch the next digit (5) from the dividend, attach it to 28 and continue: 285 / 42

Going ahead to step 6:
When dividing 285 by 42, we get 6 with a remainder of 33.
The next digit of our result is 6. 
Result so far: 7506.0
The remainder is 33 after subtracting 252 from 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Step 7:
42 goes into 330 7 times with a remainder of 36.
Record the quotient 7 as the next digit in the result. 
Result so far: 7506.7
Subtract 294 from 330 to get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Moving on to step 8:
42 goes into 360 8 times with a remainder of 24.
Use 8 as the next digit of our solution. 
Result so far: 7506.78
Deduct 336 from 360 and we're left with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 9:
If we divide 240 by 42, we get 5 and a remainder of 30.
The number 5 becomes the next digit in our result. 
Result so far: 7506.785
The remainder is 30 after subtracting 210 from 240.
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 10:
42 can be fit into 300 7 times, resulting in a remainder of 6.
The next digit of our result is 7. 
Result so far: 7506.7857
Subtracting 294 from 300 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 11:
42 can be fit into 60 1 times, resulting in a remainder of 18.
Put 1 as the next digit of the answer. 
Result so far: 7506.78571
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 12:
If we divide 180 by 42, we get 4 and a remainder of 12.
Put 4 as the next digit of the answer. 
Result so far: 7506.785714
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 13:
If we divide 120 by 42, we get 2 and a remainder of 36.
The next digit of our result is 2. 
Result so far: 7506.7857142
Subtracting 84 from 120 leaves us 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.

Let's proceed to step 14:
When dividing 360 by 42, we get 8 with a remainder of 24.
Write down 8 as next digit of the result. 
Result so far: 7506.78571428
Subtract 336 from 360 to get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

In conclusion, the division gives 7506.78571428 with a balance of 2.4e-08.