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

Describes the physical characteristics, habitats, life cycle, and behavior of different kinds of reptiles, including alligators, turtles, snakes, and lizards.

Do you have what it takes to be an athlete? Readers learn about the hard work and dedication that athletes of all levels go through to be healthy and successful. Along with stunning photos and charts and riveting facts, this Spanish-translated title includes an interview with a real-life Olympic athlete and an accessible glossary, index, and list of useful sources.

Colección de 26 cuadernos independientes de los cuatro cursos de Secundaria. Para trabajar y consolidar todos los contenidos de la ESO de acuerdo a las necesidades de cada alumno.

The US president is the face of the United States to the rest of the world. However, he or she doesn’t have unlimited power within the country. The president has certain powers given by the Constitution, including the ability to make treaties, appoint some important government officials, and veto laws. Readers learn the many duties of the president in simple, clear language appropriate for both younger readers and older readers looking for a succinct review of the topic. Fact boxes supplement the main content with important details about checks and balances, amendments, and more that affect...