Exploremos los minerales de la Tierra (Exploring Earth's Minerals)

When winter hits, many people in colder climates spend most of their time indoors. But what do wild animals do? Some animals spend winters hibernating. Beginning readers will learn what hibernation is, why some animals hibernate and others don't, and how hibernating animals prepare for their long sleep. Full-color photographs grab readers' attention and allow them to draw connections to the narrative. Readers will love learning about this mysterious, restful time in some animals' lives.

La cultura medieval islámica ha dado figuras espléndidas. Omar Jayyam, poeta y filósofo, algebrista y astrónomo, es sin duda la más fascinante de todas. Su pensamiento fue heterodoxo, su saber inmenso, su obra variadísima. De lo que nos ha llegado de su poesía no siempre es fácil distinguir lo auténtico de lo apócrifo, y de lo que sabemos de su vida, la historia de la leyenda. Su más importante aportación algebraica, la resolución sistemática de las ecuaciones cúbicas cortando cónicas, se procurará poner al alcance de un lector moderno sin alterar las ideas de fondo.

Este libro de pegatinas está diseñado para niños de tres años en adelante. Ofrece sencillas y divertidas actividades que ayudarán a los niños a descubrir los números y las formas, con la ayuda de sus personajes Disney favoritos.

In Bosques, carefully leveled text and vibrant, full-color photographs take beginning readers on a tour of a temperate forest. Readers learn about this important ecosystem and the variety of living things adapted to live there.

Meaning "River of the Colorful Birds," Uruguay is a small country in South America that is covered by crisscrossing rivers and lush hills. Home to approximately 3.5 million people, the country is often regarded as the most stable and prosperous country in Central and South America. Uruguay produces 95 percent of its electricity from renewable energy and is known as one of the most socially progressive nations in the world. Allow your readers to learn more about Uruguay's unique culture through this informative book, which features engaging sidebars and vibrant photographs.