Desafíos matemáticos

Sesenta autores, desde catedráticos de universidad hasta estudiantes de Secundaria y Bachillerato, nos presentan los cuarenta desafíos que la Real Sociedad Matemática Española propuso con motivo de su centenario.Son cuarenta estimulantes retos que avivan el ingenio. Enfrentándose a ellos, el lector se sentirá un auténtico investigador matemático.Pero no hay que asustarse. No es necesario saber muchas matemáticas. La herramienta esencial para resolver los desafíos es pensar ordenadamente.

Presents the life story of the Mexican-American labor leader who helped achieve justice for migrant farm workers by creating a union to protect their rights.

Sofía and her friends accuse someone of theft based on his appearance, but when the truth comes out, they learn a lesson about passing judgment based on superficial traits.

Life in the Southern Hemisphere is bitterly cold for most penguins, but they don't seem to mind. Most penguins live in large colonies on the coast of Antarctica or on nearby islands. Readers explore penguin colonies for themselves, learning fun facts about these beautiful birds with the help of accessible text. Readers learn how penguin families work together to feed their young and keep them warm. A helpful graphic organizer aids in reader understanding. Readers will enjoy detailed images of penguin species at home in the Antarctic with every turn of the page.

Why did the Civil War begin? Which states were part of the Union and which were part of the Confederacy? Readers will learn the answers to these questions and more as they move through this fascinating nonfiction Spanish-translated title. The easy-to-read informational text, engaging facts, and vivid images and illustrations help highlight some of the aspects that led up to the Civil War, including slavery, the Underground Railroad, abolitionists, the Fugitive Slave Act, the Dred Scott Decision, and the Lincoln-Douglas debates. The accessible table of contents works in conjunction with the...