A book I read way back was on the Trachtenberg System. Amazon has it with ISBN-10: 0313232008 and ISBN-13: 978-0313232008, but way too expensive (I thought the

A book I read way back was on the Trachtenberg System. Amazon has it with ISBN-10: 0313232008 and ISBN-13: 978-0313232008, but way too expensive (I thought the one I read was paperback). Wikipedia describes it at: http://en.wikipedia.org/wiki/Trachtenberg_system http://en.wikipedia.org/wiki/Trachtenberg_system which also mentions "Vedic mathematics," http://en.wikipedia.org/wiki/Swami_Bharati_Krishna_Tirtha%27s_Vedic_mathematics http://en.wikipedia.org/wiki/Swami_Bharati_Krishna_Tirtha%27...