Got one vedic maths book by one of my colleagues, last week. It is been written by his father, Sri Khandavalli Appala RamaMoorthy. It is amazing! You can tell the answer in a matter of seconds for the ones you need to take some minutes using the usual way. For the huge numbers involving multiplication, division, square roots etc. Really cool.
Used to consume some time while doing calculations during the competitive examns like Engineering entrance (EAMCET). If I knew this kind of vedic maths, I might have gotten one of the top ten ranks instead of my rank, three hundred. No doubt about it.