Question 940452
<pre>
0,1,2,3,4,5,6,7,8 and 9

1 way to pick the 1st digit (as 0).
9 ways to pick the 2nd digit.
8 ways to pick the 3rd digit.
7 ways to pick the 4th digit.
6 ways to pick the 5th digit.
5 ways to pick the 6th digit.
4 ways to pick the 7th digit.
3 ways to pick the 8th digit.

1×9×8×7×6×5×4×3 = 9!/2! = 181440

Edwin</pre>