This book is everything possible on manipulating multi digits to single digits. This is the essence of 1 of 16 Vedic Sutras that means 'Digital Sums' or Digital Compression. There is a whole chapter on Multiplication by 11 which is set out with questions and answers. This book was the result of a 6 months Teacher Training course held in Byron Bay, and this book was an attempt to write the new material in a format with questions and answers. This is the essence of Vedic Mathematics which can be done mentally, via pattern recognition, or it can be done by one single line of intelligent arithmetic.