We look at the division of 13143 by 42 
We want to divide 13143 by 42.

Advancing to step 1:
If we divide 1 by 42, we get 0 and a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Take the next digit (3) from the dividend and append it to 1, then repeat: 13 / 42

Step 2:
42 goes into 13 0 times with a remainder of 13.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 13 and we're left with 13.
Append the next digit (1) from the dividend to 13 and continue with: 131 / 42

Moving on to step 3:
131 divided by 42 is 3 with a remainder of 5.
The next digit of our result is 3. 
Result so far: 3.0
Subtracting 126 from 131 leaves us with 5.
Bring next digit (4) of the dividend behind the 5 and repeat the process: 54 / 42

Step 4:
If we divide 54 by 42, we get 1 and a remainder of 12.
Put 1 as the next digit of the answer. 
Result so far: 31.0
Subtracting 42 from 54 leaves us with 12.
Take the next digit (3) from the dividend and append it to 12, then repeat: 123 / 42

Step 5:
123 divided by 42 is 2 with a remainder of 39.
The number 2 becomes the next digit in our result. 
Result so far: 312.0
Deduct 84 from 123 and we're left 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.

Moving on to step 6:
390 divided by 42 is 9 with a remainder of 12.
Write down 9 as next digit of the result. 
Result so far: 312.9
If we subtract 378 from 390, we get 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 7:
When dividing 120 by 42, we get 2 with a remainder of 36.
Record the quotient 2 as the next digit in the result. 
Result so far: 312.92
If we take 84 away from 120, 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.

Moving on to step 8:
The number 42 fits into 360 8 times, leaving a remainder of 24.
Write down 8 as next digit of the result. 
Result so far: 312.928
If we take 336 away from 360, we end up 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:
When dividing 240 by 42, we get 5 with a remainder of 30.
Record the quotient 5 as the next digit in the result. 
Result so far: 312.9285
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.

On to step 10:
42 goes into 300 7 times with a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 312.92857
If we take 294 away from 300, we end up 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:
60 divided by 42 is 1 with a remainder of 18.
The number 1 becomes the next digit in our result. 
Result so far: 312.928571
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:
180 divided by 42 is 4 with a remainder of 12.
The next digit of our result is 4. 
Result so far: 312.9285714
Deduct 168 from 180 and we're left 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.

Moving on to step 13:
When dividing 120 by 42, we get 2 with a remainder of 36.
The next digit of our result is 2. 
Result so far: 312.92857142
If we subtract 84 from 120, we 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.

Our division results in 312.92857142 with a remaining 3.6e-08.