 An estimated 140,000 of the tapes and DVDs were sent to educational institutions around the world, and have been viewed by approximately 10 million people over the last 20 years.The series is also distributed through the Mathematical Association of America and NASA's Central Operation of Resources for Educators (CORE).In addition, over half of the states in the US have received master copies of the videotapes so they can produce and distribute copies to their various educational institutions.