“I lost my sock!” says Fox. “Have you seen it?” So begins Ox’s ridiculous attempts to help Fox find his missing sock. He presents each new option just before the page turn so the reader has a moment to decide for him or herself whether Ox has, in fact, found Fox’s sock. At its heart, I Lost My Sock! is the story of a funny misunderstanding between friends. But it’s also about pattern, color, and shape recognition; comparing and contrasting; and object identification. Mastery of these skills enriches a child’s vocabulary, prepares him to understand letters and numbers, and helps him gain a better sense of the world around him. Elio’s bold, geometric character designs further reinforce the early math concepts hinted at in this book.