In Jabar’s smudgy, action-filled illustrations for this MathStart entry, Zoe is a charming, freckled “greatest gymnast of them all”—in her own words—and demonstrates her expertise while introducing opposites: over, under, high, low, backward, forward, up, down, inside, outside, near, far. She tumbles across the mat, along the balance beam, and around the high bar. Adults looking on will have to hope that this is all in Zoe’s imagination, for she performs without spotters; more importantly, Murphy (Lemonade for Sale, 1998, etc.) never links the idea of opposites to math. An exuberant concept book on its own, it may confuse those looking for math-oriented enlightenment. (Picture book. 3-5)