Hiraku Hirokazu, a world-renowned mathematician, reveals a practical method for studying mathematics, drawing on his own experiences with math since childhood. (From the book jacket) Anyone with a middle school level of math knowledge should be able to enjoy this book. (From the preface) Published by Sankei Publishing / 1980 / First Edition There are no noticeable scratches or stains (almost unused), but there is overall yellowing due to aging.