Little children are irrepressibly curious. One of the first words a child says is invariably “why”. Why is the water cold? Why does the swing swing? Why must I pedal slowly going down hill? Why is there a moon? Why does it grow dark? Why does fog come out of your mouth when it’s cold?

Unless such questions are answered with equal vitality, in a lively way that children can understand and appreciate, this curiosity is dimmed and learning becomes a chore.

This is why this non-fiction series from France and published here by Oxford University Press is so welcome. The four books are aimed at six to eight-year-olds and offer a thoroughly absorbing exploration of some of the key subjects which absrb young minds.

They are beautifully designed, with activities, games and riddles, mini-books within books, tricks and tips, lift-the-flaps, turn-the-wheels and peep-holes. The paper engineering is clever, but simple and durable, designed to good effect rather than for the sake of gadgetry. The books really do answer some of those big questions in a practical and engaging way with just the right pitch and tone.

The text is clear and accurate, yet lyrical and entertaining. The illustrations are witty, inventive and expressive, and the engineering plays the kind of clever tricks children adore.

For example, in the book on senses, lips open out into a tongue covered in pictures of different kinds of food - bitter, sweet, savoury.

These books provide endless opportunities for discussion and teaching and lots of fun. A must-have addition to home or classroom.

ELAINE WILLIAMS