This is the second of the authors' successful attempts to exercise the imagination of young children. An absorbing and useful game for a rainy day, Let's Imagine up Thing introduces basic geometric shapes, the circle, square, line and triangle, and invites us to think up objects that conform wholly or in part to these shapes. As in the first book, encouragement is gradual -- three or four large objects incorporating the shape appear first and then a great assortment of familiar things, with the shape outlined in black. Equipped with crayons and paper (or an avid co-partner) the child should be 'carin' to add his own collection to these handsome groups. The authors' broad interpretation of a line sees it curving and zig-zagging -- herein may lie the only possible confusion.