648390 ÷ 18 
We want to figure out the number of times 648390 can be divided by 18.

Step 1:
18 goes into 6 0 times with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 18

Step 2:
When dividing 64 by 18, we get 3 with a remainder of 10.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtracting 54 from 64 leaves us with 10.
Take the next digit (8) from the dividend and append it to 10, then repeat: 108 / 18

Step 3:
If we divide 108 by 18, we get 6 and a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 36.0
Subtracting 108 from 108 leaves us with 0.
Fetch the next digit (3) from the dividend, attach it to 0 and continue: 3 / 18

Advancing to step 4:
18 can be fit into 3 0 times, resulting in a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 360.0
Subtracting 0 from 3 leaves us with 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 18

Going ahead to step 5:
18 goes into 39 2 times with a remainder of 3.
Write down 2 as next digit of the result. 
Result so far: 3602.0
The remainder is 3 after subtracting 36 from 39.
Append the next digit (0) from the dividend to 3 and continue with: 30 / 18

Moving on to step 6:
18 can be fit into 30 1 times, resulting in a remainder of 12.
Use 1 as the next digit of our solution. 
Result so far: 36021.0
If we subtract 18 from 30, we 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.

Going ahead to step 7:
The number 18 fits into 120 6 times, leaving a remainder of 12.
The next digit of our result is 6. 
Result so far: 36021.6
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.

On to step 8:
18 can be fit into 120 6 times, resulting in a remainder of 12.
The number 6 becomes the next digit in our result. 
Result so far: 36021.66
If we subtract 108 from 120, we 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.

The final result is 36021.66 with a remainder of 0.012.