We're dividing 420340 by 18 
We want to divide 420340 by 18.

Going ahead to step 1:
4 divided by 18 is 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 4, we get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 18

Moving on to step 2:
When dividing 42 by 18, we get 2 with a remainder of 6.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtract 36 from 42 to get 6.
Take the next digit (0) from the dividend and append it to 6, then repeat: 60 / 18

On to step 3:
If we divide 60 by 18, we get 3 and a remainder of 6.
Write down 3 as next digit of the result. 
Result so far: 23.0
If we take 54 away from 60, we end up with 6.
Append the next digit (3) from the dividend to 6 and continue with: 63 / 18

Moving on to step 4:
If we divide 63 by 18, we get 3 and a remainder of 9.
The number 3 becomes the next digit in our result. 
Result so far: 233.0
Subtract 54 from 63 to get 9.
Take the next digit (4) from the dividend and append it to 9, then repeat: 94 / 18

On to step 5:
94 divided by 18 is 5 with a remainder of 4.
The next digit of our result is 5. 
Result so far: 2335.0
Subtract 90 from 94 to get 4.
Bring next digit (0) of the dividend behind the 4 and repeat the process: 40 / 18

Going ahead to step 6:
If we divide 40 by 18, we get 2 and a remainder of 4.
The next digit of our result is 2. 
Result so far: 23352.0
If we take 36 away from 40, we end up 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.

Let's proceed to step 7:
18 goes into 40 2 times with a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 23352.2
Subtract 36 from 40 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 8:
18 can be fit into 40 2 times, resulting in a remainder of 4.
Record the quotient 2 as the next digit in the result. 
Result so far: 23352.22
Deduct 36 from 40 and we're left 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.

Our division results in 23352.22 with a remaining 0.004.