We're dividing 126165 by 42 
Let's see how many times 42 fits into 126165.

Going ahead to step 1:
The number 42 fits into 1 0 times, leaving a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 42

Step 2:
12 divided by 42 is 0 with a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 12 and we're left with 12.
Fetch the next digit (6) from the dividend, attach it to 12 and continue: 126 / 42

On to step 3:
If we divide 126 by 42, we get 3 and a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
If we subtract 126 from 126, we get 0.
Include the next digit (1) from the dividend after 0, then repeat: 1 / 42

Step 4:
The number 42 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 30.0
Subtract 0 from 1 to get 1.
Append the next digit (6) from the dividend to 1 and continue with: 16 / 42

Going ahead to step 5:
16 divided by 42 is 0 with a remainder of 16.
Use 0 as the next digit of our solution. 
Result so far: 300.0
Deduct 0 from 16 and we're left with 16.
Grab the next digit (5) from the dividend, add it to 16, then carry on: 165 / 42

Let's proceed to step 6:
42 goes into 165 3 times with a remainder of 39.
Use 3 as the next digit of our solution. 
Result so far: 3003.0
Deduct 126 from 165 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.

Going ahead to step 7:
42 can be fit into 390 9 times, resulting in a remainder of 12.
Put 9 as the next digit of the answer. 
Result so far: 3003.9
Deduct 378 from 390 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.

Going ahead to step 8:
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: 3003.92
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.

Let's proceed to step 9:
42 can be fit into 360 8 times, resulting in a remainder of 24.
Record the quotient 8 as the next digit in the result. 
Result so far: 3003.928
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.

Going ahead to step 10:
240 divided by 42 is 5 with a remainder of 30.
Use 5 as the next digit of our solution. 
Result so far: 3003.9285
If we take 210 away from 240, we end up with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 11:
42 goes into 300 7 times with a remainder of 6.
The next digit of our result is 7. 
Result so far: 3003.92857
If we subtract 294 from 300, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 12:
42 goes into 60 1 times with a remainder of 18.
Put 1 as the next digit of the answer. 
Result so far: 3003.928571
If we take 42 away from 60, we end up 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.

Step 13:
42 can be fit into 180 4 times, resulting in a remainder of 12.
The number 4 becomes the next digit in our result. 
Result so far: 3003.9285714
Subtracting 168 from 180 leaves us 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 14:
42 can be fit into 120 2 times, resulting in a remainder of 36.
Use 2 as the next digit of our solution. 
Result so far: 3003.92857142
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.

The final result is 3003.92857142 with a remainder of 3.6e-08.