646666 divided by 18 
Let's see how many times 18 fits into 646666.

Moving on to step 1:
18 can be fit into 6 0 times, resulting in a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Append the next digit (4) from the dividend to 6 and continue with: 64 / 18

Going ahead to step 2:
If we divide 64 by 18, we get 3 and a remainder of 10.
The next digit of our result is 3. 
Result so far: 3.0
Subtract 54 from 64 to get 10.
Append the next digit (6) from the dividend to 10 and continue with: 106 / 18

On to step 3:
106 divided by 18 is 5 with a remainder of 16.
Write down 5 as next digit of the result. 
Result so far: 35.0
Subtract 90 from 106 to get 16.
Grab the next digit (6) from the dividend, add it to 16, then carry on: 166 / 18

Going ahead to step 4:
18 goes into 166 9 times with a remainder of 4.
Record the quotient 9 as the next digit in the result. 
Result so far: 359.0
Deduct 162 from 166 and we're left with 4.
Take the next digit (6) from the dividend and append it to 4, then repeat: 46 / 18

Advancing to step 5:
18 goes into 46 2 times with a remainder of 10.
Use 2 as the next digit of our solution. 
Result so far: 3592.0
Subtract 36 from 46 to get 10.
Grab the next digit (6) from the dividend, add it to 10, then carry on: 106 / 18

Let's proceed to step 6:
When dividing 106 by 18, we get 5 with a remainder of 16.
The number 5 becomes the next digit in our result. 
Result so far: 35925.0
Deduct 90 from 106 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 7:
If we divide 160 by 18, we get 8 and a remainder of 16.
The number 8 becomes the next digit in our result. 
Result so far: 35925.8
Deduct 144 from 160 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

On to step 8:
160 divided by 18 is 8 with a remainder of 16.
Write down 8 as next digit of the result. 
Result so far: 35925.88
Subtracting 144 from 160 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

The final outcome is 35925.88, with a leftover of 0.016.