For the past decade or so, there's been a decline in the number of mathematics students in high schools in Australia. But one teacher is giving new life to the subject through his thoroughly engaging ...

GLOVERSVILLE - At Gloversville High School, he’s "Mr. Martin." Online, he’s "Ludus." That's the handle 24-year-old Joshua Martin came up with when he first began making math tutorial YouTube videos.

The brainchild of MIT graduate and a successful financial analyst Salman Khan, the academy was launched in 2006 when Khan decided to post mathematics tutorials for his cousin Nadia on YouTube. Khan ...