La historia de los sistemas numéricos: Valor posicional (The History of Number Systems: Place Value)

Brief biographies of well-known men and women, from ancient time to the present day, who made significant contributions in various fields.

Describes, in text and illustrations, the technological challenges involved in the design and construction of skyscrapers, oil rigs, nuclear reactors, and other complicated structures.

Guía ilustrada de los cielos, los infiernos y las tierras de los muertos que han imaginado a lo largo de la historia las distintas culturas y religiones de todo el mundo: mapas, pinturas y relatos para realizar un fascinante recorrido por la geografía, la historia y los seres sobrenaturales que pueblan los distintos mundos del más allá. Ya se trate de los trece cielos aztecas, del inframundo taoísta chino de los "fantasmas hambrientos" o del "infierno del gallo llameante" de la mitología budista japonesa, se reúne una gran variedad de creencias y representaciones sobre la vida después ...

Rain, sunshine, warm fronts, and cold fronts. Have you ever listened to a weather report? Knowing the weather can help us plan ahead. But reporters aren’t the only ones who can track weather. You can, too! This nonfiction Spanish book explores the subject of meteorology in depth, and introduces students to important scientific concepts and vocabulary like anemometer, barometer, air pressure, warm front, cold front, rain gauge, probability, Celsius, Fahrenheit, and more. The colorful images, diagrams, sidebars, and text features will keep students connected to the text. Aligned to state and...