PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 725; Flight Crew Type 45
Communication Breakdown
Conflict NMAC
Human Factors
While enroute (cruise); an aircraft (C182 tail dragger) suddenly passed over and overtook us in our Piper Warrior at a distance that was close enough to almost cover the wind screen.  The student and I were discussing where we would land in the case of an emergency at the time of the incident.  We had ADS-B In via ForeFlight and did not see any aircraft around (electronically) just prior to the incident. Weather conditions were clear and we were scanning outside for traffic (visually). Evasive action was not taken as the aircraft passed over us at a slight angle and was to our left side by the time we were able to react.  The aircraft then turned to the left (south).  We were monitoring 122.9 (ZZZ uses 122.8 which is what I should have been monitoring at that time).  My fault in the incident was that I should have been monitoring and announcing on 122.8 instead of 122.9.  I do not believe that the Cessna saw us or even realized that we were sharing the same real estate.  In the future; I will be more attentive to local frequencies and stay at a higher altitude in that area.
Flight Instructor flying Piper Warrior reported a NMAC in cruise.