Thirds and Differences

Here's a nice little problem that can be figured out using algebra or using a little guess-work and a bit of luck.  It should be suitable for older elementary school or high school students.

1  2  3  4  5  6  7  8  9

Arrange the digits 1-9 so that the first 3 form a number that is 1/3 of the number formed by the last three and the three digits in the middle form a number that is the difference between them.

The numbers are as they appear, not summed.


There are 362880 ways to arrange the nine digits and 4 valid solutions to this puzzle.  Good luck!