We're dividing 151321 by 42 
Our goal is to divide 151321 by 42.

Let's proceed to step 1:
When dividing 1 by 42, we get 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Include the next digit (5) from the dividend after 1, then repeat: 15 / 42

On to step 2:
42 can be fit into 15 0 times, resulting in a remainder of 15.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 15 and we're left with 15.
Fetch the next digit (1) from the dividend, attach it to 15 and continue: 151 / 42

Going ahead to step 3:
If we divide 151 by 42, we get 3 and a remainder of 25.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtracting 126 from 151 leaves us with 25.
Grab the next digit (3) from the dividend, add it to 25, then carry on: 253 / 42

Moving on to step 4:
The number 42 fits into 253 6 times, leaving a remainder of 1.
Use 6 as the next digit of our solution. 
Result so far: 36.0
Subtract 252 from 253 to get 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 42

Let's proceed to step 5:
42 can be fit into 12 0 times, resulting in a remainder of 12.
Write down 0 as next digit of the result. 
Result so far: 360.0
If we take 0 away from 12, we end up with 12.
Include the next digit (1) from the dividend after 12, then repeat: 121 / 42

On to step 6:
121 divided by 42 is 2 with a remainder of 37.
Use 2 as the next digit of our solution. 
Result so far: 3602.0
Subtract 84 from 121 to get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Step 7:
42 goes into 370 8 times with a remainder of 34.
Record the quotient 8 as the next digit in the result. 
Result so far: 3602.8
If we take 336 away from 370, we end up with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Step 8:
If we divide 340 by 42, we get 8 and a remainder of 4.
Write down 8 as next digit of the result. 
Result so far: 3602.88
Subtracting 336 from 340 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

After the division, we end up with 3602.88 and a remainder of 0.004.