This is a book of games based around the number one, and is full of fun illustrations and ideas that are easily accessible to children. It is aimed at one year old children, and its educational value lies in its use of an original and entertaining strategy based on interaction between the child and the book, whereby the child places the finger which corresponds to their age in the hole on each page. In this way, they discover that the little pig has 1 tail, that the flamingo stands on 1 leg, that the snowman has 1 nose... This book is a wonderful resource which helps children to refine pyschomotor skills and to interiorise numbers in a meaningful way.