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

El regalo de un hechicero hace que la fortuna de Juan crezca de uno en uno, de dos en dos, luego de tres en tres y de cuatro en cuatro, despu s cada v z m s y m s, desafi ndote a llevar un registro de su riqueza.

How do you truly engage students in learning history? When students make personal connections to the subject, they’re much more motivated to learn. This Spanish book provides firsthand accounts of history that give personal insights into historical events. Students will learn about the U.S. Constitution, the Articles of Confederation, the Connecticut Compromise, and the Bill of Rights. With a visually appealing layout, this book features captivating text, fun facts, sidebars, and time lines that help students grasp the essential concepts they need to know at their grade level. Packed with...

Describes the ancient giant kangaroo of Australia's distant past that was five times the size of today's largest kangaroos. Discusses how the animal lived and how it became extinct.

This book describes dump trucks called off-highway trucks, explaining their operating equipment and dumping beds, fuel, and jobs.