We're dividing 643616 by 18 
We want to divide 643616 by 18.

Let's proceed to step 1:
6 divided by 18 is 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 18

Moving on to step 2:
64 divided by 18 is 3 with a remainder of 10.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 54 from 64 and we're left with 10.
Include the next digit (3) from the dividend after 10, then repeat: 103 / 18

On to step 3:
If we divide 103 by 18, we get 5 and a remainder of 13.
Record the quotient 5 as the next digit in the result. 
Result so far: 35.0
If we subtract 90 from 103, we get 13.
Fetch the next digit (6) from the dividend, attach it to 13 and continue: 136 / 18

Going ahead to step 4:
The number 18 fits into 136 7 times, leaving a remainder of 10.
The next digit of our result is 7. 
Result so far: 357.0
Subtracting 126 from 136 leaves us with 10.
Include the next digit (1) from the dividend after 10, then repeat: 101 / 18

On to step 5:
18 goes into 101 5 times with a remainder of 11.
The next digit of our result is 5. 
Result so far: 3575.0
If we subtract 90 from 101, we get 11.
Bring next digit (6) of the dividend behind the 11 and repeat the process: 116 / 18

Going ahead to step 6:
116 divided by 18 is 6 with a remainder of 8.
Write down 6 as next digit of the result. 
Result so far: 35756.0
Deduct 108 from 116 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 7:
80 divided by 18 is 4 with a remainder of 8.
The next digit of our result is 4. 
Result so far: 35756.4
The remainder is 8 after subtracting 72 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 8:
18 can be fit into 80 4 times, resulting in a remainder of 8.
The number 4 becomes the next digit in our result. 
Result so far: 35756.44
The remainder is 8 after subtracting 72 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

The final result is 35756.44 with a remainder of 0.008.