National Library Virtual Manipulatives for Interactive Mathematics
http://nlvm.usu.edu/en/nav/index.html
This site contains all sorts of interactive mathematics games and enrichment activities that can be used in the classrooms or for after school tutoring.

Web Math.com
http://www.webmath.com/index.html
This site will work the math problem out for you and also give you the explanation for it.

Telling Time
Students learn how to tell time on analog clocks. There is an interactive quiz, so students will see how well they paid attention to the presentation.
http://breitlinks.com/time/

The Origins of Math
Famous math inventors were nearly all from Ancient Greece, the birthplace of geometry and trigonometry. The instructor uses a white board to discuss not the inventors themselves, but the specific math and it origins.
http://www.watchknowlearn.org/Video.aspx?VideoID=16613