"Ballenas" is an informational, non-fiction book about whales that introduces kids of all ages to the topic. The book features key vocabulary such as mammals, blowhole, species, toothed whales, baleen whales, and killer whales. The book also covers the effects of human activity on the habitat and survival of whales and other ocean animals. Each page features a full-size, real-life image, and many pages feature original graphics and graphs that appear alongside these images. The book is written at a 1st-grade reading level, and its photos are age-appropriate to also accommodate older students struggling with reading. This book has also been tremendously successful with older immigrant students with interrupted formal education still learning to read in their native language. This book is also available in Spanish.