Cuaderno Ágora de Matemáticas 4

A scientific look at the natural processes that create waterfalls, and where they are likely to form.

Mysterious ancient ruins, hidden deep in the jungle of southern Mexico In May 1840, explorers John Stephens and Frederick Catherwood road their mules along a steep, muddy jungle path. They were hoping to find the ruins of an ancient, deserted site in Mexico they knew only from visitors’ accounts. Through the trees, they spied the remains of a crumbling stone palace. Palenque! In the weeks they spent there, the men discovered intricately designed buildings and mysterious glyphs, or symbols. Who built this city? What did the glyphs mean? The questions remained largely unanswered until the...

Esta es una colección de pequeños alienígenas guardianes de la naturaleza que salen de su planeta en la búsqueda de la mayor contaminador del universo, el malvado Zirt Zlunder. Se escapa y viene a parar en la Tierra. En este libro Zirt Zlunder el contaminador está contaminando el Ártico, donde se escondió. Los Pequeños Guardianes Ellos encuentran Zirt Zlunder e impedirán que contaminen el Ártico. ¿Tendrán éxito? ¿Deberán arrestar a Zirt Zlunder el terrible contaminador?

Many animals live in water, but only some can be defined as fish. Twenty-eight thousand species of fish exist, each with different characteristics. Readers from grades one through four will learn that fish have a distinct impact on their ecosystem and will see how fish survive when well-adapted to an uncompromised environment. Beautiful photographs demonstrate the great diversity of fish and accompany intellectually stimulating explanations of their varying roles and traits. From page to page, what a fish is unfolds in vocabulary call-outs, insightful questions, and relatable...