Hi Candace,
Here's a few of suggestions to show a count of the open Tasks on a Project:
1. on a Project's Task tab, filter to Tasks with blank Actual End Dates (and, I suspect, Number of Childen = 0) and either look at the bottom for the total, or group by Project -- the count then appearing in parentheses
2. Same idea, but on a Task report, to see the counts by the Projects (of interest)
3. Consider our UbertCalc solution, which can automatically calculate the count and store it at the Project level (among other grooviness).
Regards,
Doug