¿Por qué hibernan los animales? (Why Animals Hibernate)

Diamonds and salt are both minerals, but diamonds are more rare than salt. Curious readers will learn what physical and chemical conditions must be present for minerals to form. They'll discover how minerals are identified and how they are used in daily life. Informative and interesting text presents readers with this science content in a fun way. A graphic organizer shows how different minerals are identified and fact boxes provide readers with exciting supplementary information.

When rocks change because of environmental conditions, the new rocks are called metamorphic rocks. A rock's chemical or physical makeup may change because of conditions such as temperature, stress, or pressure. Your readers will learn fascinating facts including where metamorphic rocks are most commonly found, the different types of metamorphism, and how metamorphic rocks are identified. Full-color photographs depict these rocks in nature. A helpful graphic organizer shows how these fascinating rocks form.

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

Simple text and illustrations introduce children to number concepts and teach them how to identify numbers.

El nuevo libro de la colección Un mar de historias recorre la vida del escritor Lope de Vega a partir de las aventuras de Ana y Miguel, dos niños del año 3000, que se trasladan al pasado con su máquina del tiempo para que sea el mismo Lope de Vega quien les hable. De esta manera pueden conocer de cerca al autor de "Peribáñez y el comendador de Ocaña", "El caballero de Olmedo" o "Fuenteovejuna", por citar sólo algunas obras.

Este libro ilustrado para niños contiene juegos con dados, cartas, matemáticas y otras cosas para revelar los poderes mentales que poseen los lectores.