Math teacher Martha Strever has seen educational trends come and go at Linden Avenue Middle School in Red Hook, Dutchess County. From the metric system in the 1970’s, to modern math and common core, over the years the only constant in the classroom has been Strever herself. That consistency hit a milestone this fall when Strever celebrated 64 years as an in-service educator — all spent in the Red Hook Central School district where she started as a student teacher in 1960. And as long as her health allows, the Red Hook Faculty Association member has no plans to retire.