I first encountered this book when I was in elementary school, long before I knew and appreciated the role Martin Gardner has played in the mathematical education of the general public. I found the problems compelling and concentrated on them to the exclusion of almost everything else. I was slow to supper, slow to bed and fidgeted about them after the lights went out. Even though it was first published in 1959, the problems in this book remain classical gems and are still able to stimulate the right set of brain cells in the young mind. It, like all other work by the master Gardner, will never grow old.