We're dividing 421131 by 18 
Let's see how many times 18 fits into 421131.

Going ahead to step 1:
18 can be fit into 4 0 times, resulting in a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 18

On to step 2:
42 divided by 18 is 2 with a remainder of 6.
The next digit of our result is 2. 
Result so far: 2.0
Subtracting 36 from 42 leaves us with 6.
Include the next digit (1) from the dividend after 6, then repeat: 61 / 18

Let's proceed to step 3:
When dividing 61 by 18, we get 3 with a remainder of 7.
The number 3 becomes the next digit in our result. 
Result so far: 23.0
Deduct 54 from 61 and we're left with 7.
Fetch the next digit (1) from the dividend, attach it to 7 and continue: 71 / 18

Step 4:
The number 18 fits into 71 3 times, leaving a remainder of 17.
The next digit of our result is 3. 
Result so far: 233.0
Subtract 54 from 71 to get 17.
Take the next digit (3) from the dividend and append it to 17, then repeat: 173 / 18

On to step 5:
173 divided by 18 is 9 with a remainder of 11.
Use 9 as the next digit of our solution. 
Result so far: 2339.0
If we take 162 away from 173, we end up with 11.
Append the next digit (1) from the dividend to 11 and continue with: 111 / 18

Going ahead to step 6:
The number 18 fits into 111 6 times, leaving a remainder of 3.
Record the quotient 6 as the next digit in the result. 
Result so far: 23396.0
The remainder is 3 after subtracting 108 from 111.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 7:
18 can be fit into 30 1 times, resulting in a remainder of 12.
Record the quotient 1 as the next digit in the result. 
Result so far: 23396.1
The remainder is 12 after subtracting 18 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 8:
18 can be fit into 120 6 times, resulting in a remainder of 12.
The next digit of our result is 6. 
Result so far: 23396.16
If we take 108 away from 120, 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.

Going ahead to step 9:
18 can be fit into 120 6 times, resulting in a remainder of 12.
The next digit of our result is 6. 
Result so far: 23396.166
Subtract 108 from 120 to 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.

In conclusion, the division gives 23396.166 with a balance of 0.0012.