Concept books for little children are a specialty of versatile Ontario author-illustrator Marthe Jocelyn, and this first collaboration with her art-student daughter Nell is a delightful development in the genre. The younger Jocelyn’s imaginative collages help create a book rich in playful details, with a storyline told through pictures that provide depth to the concepts explored in the text.

Using examples taken from the world of a small child, Ones and Twos introduces the ideas of numbers and pairing. Two girls walk through the park, sharing a snack (one bun, two bites), and are followed by a robin. There are two eggs at the start of the book, but when the robin returns at the end, there are two downy heads in the nest. The two girls share one prize, a pink feather that floats down from the robin’s breast, but in the final picture we see that the robin has a prize, too: it has brought the girl’s hair ribbon home to her nestlings.

Although the text is very spare, words like “lone,” “swoop,” and “chums” provide verbal interest. The variety of colours and textures add depth and fascination to the collage images. A border running along the bottom containing objects related to what the girls are doing in the main picture, develops the theme of ones and twos. As the girls drop crumbs from their snack, the border shows other discarded items: one safety pin, two buttons, one candy wrapper, two bottle tops, and so on.

Sophisticated and yet endearingly simple, Ones and Twos can be enjoyed by both very young children and the adults who read it with them.