A past issue of MathNEXUS recommended Dave Marain's MathNotations. I hope you visited the site and found some useful information there.
Now, Dave is conducting a FREE "online" Math Contest for students in Grades 7-12. Unfortunately, the timing is quite short, as the contest occurs on Tuesday, February 3rd, with registration needed by January 27th (not much notice!).
Competent middle school students should be able to "handle" 1 or 2 of the 6 questions. However, the contest is directed more towards the Algebra II student.
The contest is different in that it is FREE, team-based (up to 6 participants), has multi-part questions (like the investigations on his blog) and contains some open-ended parts requiring verbal explanations. Calculators are allowed.
Any interested school district or mathematics teacher can register simply by emailing Dave to get a registration form.
On the day of the contest, participating students will type their answers/solutions in Word. Their sponsor/proctor will then email Dave the form as an attachment at the end of the day on February 3rd.
To learn more or request a registration form, consult Dave's web site. Have fun....