La regla mola (si sabes cómo funciona)

Animalanzas incluye casi doscientos acertijos de Hispanoamérica, ideales para leer y reir en los ratos libres.

Margarita es una chica de trece años que se siente sola. Un día, empieza a cartearse con otra chica de su edad, que está muy triste porque han secuestrado a su hermano. Margarita, por casualidad, descubre quiénes son los secuestradores.

Mars is perhaps the most thrilling planet these days. With rovers exploring its surface and manned missions in the works, people are wondering if Mars is our next home! In this highinterest book, readers will learn more about Earth's neighbor, including what its climate and surface are like, why it's called the Red Planet, and about the recent discovery of water on its surface. They'll learn all this while solving "Your Mission" math problems that complement and support the text. This motivating volume is an engaging way to explore key aspects of science and math curricula.

Defines pulleys, explains their functions, and suggests simple experiments to demonstrate how they work.