Leo teaches his cat Pallas all about circles by applying his knowledge of geometry to their Stone Age world. Engaging illustrations and stories provide a fun introduction to math concepts, including tangents, ellipses, and more. Information boxes accompany each story to explore real applications of circles in the natural and designed world.

Leo is brilliant at: Curves the tooth collection -- Rings -- Circles in action seeing circles -- Semicircles half circles -- Pie charts -- Spinning circles round and round -- Wheels -- Spinning blades -- Wheels in wheels -- Tangents -- Concentric circles circles inside circles -- The boomerang ellipses -- Spirals -- Coils and loops.