Experimentos sencillos sobre el tiempo

Beginning readers will be captivated by the creatures they meet in this Spanish translation of Prehistoric Creatures. The simple text describes ancient animals that swam the seas, soared through the skies, and roamed the Earth long before people existed. Each book describes a group of dinosaurs that shared one or two fascinating features. Dazzling illustrations help bring these amazing creatures to life!

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.

Weather is an important science concept at the early elementary level. Recognizing and identifying kinds of weather requires observational skills and certain vocabulary terms. This bright volume allows young meteorologists to correlate weather in carefully selected photographs with descriptive weather vocabulary, such as rainy, sunny, and foggy. It's never too early to tackle this essential STEM theme!

In 1846, travelers heading for California became trapped high in the mountains of the Sierra Nevada. Snowdrifts surrounded their shelters, and food supplies dwindled. How they stayed alive remains one of the most gruesome stories in US history. However, some facts that have come to light recently through archaeological digs will surprise even those who think they know the story. This gripping book, including maps and images of the era, tells the true account of the doomed Donner party.