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

A guide for adolescent boys that offers advice on dating, sex, body changes, and social life. "Manual de supervivencia para hombres."

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.

Discusses Things That Rot And Break Down And Things That Don't, How Decomposing Things May Feed Insects Or Animals Or Help The Soil, And Talks About Recycling.

Computer science is all around us, at school, at home, and in the community. This book gives readers the essential tools they need to understand the computer science concept of algorithms and procedures. Brilliant color photographs and accessible text will engage readers and allow them to connect deeply with the concept. The computer science topic is paired with an age-appropriate curricular topic to deepen readers' learning experience and show how algorithms and procedures work in the real world. In this book, readers will learn how flowcharts can be used to teach people how to complete a...