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

Kids love to play games. Let's explore kids' favorite games from around the world. The Días de Descubrimiento (Discovery Days) series is perfect for young learners in prekindergarten through grade 2. These 16-page books give readers an accessible introduction to nonfiction reading. Color photographs and fun, factual examples will grab the attention of young readers and help strengthen reading comprehension skills.

With its accessible question-and-answer format, this dynamic reference answers many questions posed by children and helps parents find the right way to explain a variety of complex concepts. Con su formato acesible de preguntas y respuestas, esta referencia dinámica contesta muchas preguntas que tienen los niños y ayuda a los padres a encontrar la manera apropiada de explicar una variedad de conceptos complejos.

If a person were ever face-to-face with a huge, hungry animal with sharp teeth, they probably wouldn’t care exactly what that animal was! But from a safe location, can we tell whether it was a crocodile or alligator that wanted to take a bite? By examining their jaw structure, teeth, and other physical features, we can easily tell these two animals apart! Graphic organizers and amazing images highlight each animal’s habitat and other small differences between the two fearsome creatures, showing readers just what creature is lurking below the waters.

La hibernación es un ciclo que algunos animales hacen cada año. La mayoría de la gente sabe que los osos hibernan. ¿Pero por qué hibernan? ¿Y qué otros animales hibernan? Hibernation is a cycle that some animals go through every year. Most people know that bears hibernate. But why do they hibernate? And what other animals hibernate?