Simple Views Calc Question

Hi,

I'm just learning the depths of drupal. I'd like to borrow functionality from this page: http://drupal.org/project/views_calc

In the issues block, under the search bar it says "70 open, 171 total." Does anybody know how this is generated? I know Drupal.org uses the project module and this feature is probably connected to that. But I was hoping to be able to something like this using my own content types.

Is Views Calc the thing I want here? Can anybody with more experience than I point me in the right direction? Many thanks!