Desafíos matemáticos

El 11 de febrero de 1990, después de haber luchado toda su vida contra el Apartheid y tras 27 años en prisión, Nelson Mandela fue finalmente liberado. La historia de Mandela, que finalmente se ha convertido en uno de los más grandes líderes mundiales, es también la difícil historia de Sudáfrica.

Winter, spring, summer, and fall. Each season has its unique identifying features as well as its exciting activities. Readers will become well acquainted with these as they learn about the four seasons from this beneficial book. They'll also decide which is their favorite season. Thoughtfully chosen photographs correlate with the achievable text and illustrate the characteristics of each season.

"Amphibians have some of the most interesting life cycles on Earth. The metamorphosis frogs, toads, salamanders, newts, and caecilians go through has many steps that readers need to understand and remember. This book offers a concise overview of the general amphibian life cycle as well as representative examples of the many species within the animal group. Most importantly, the accessible language is paired with diagrams of the steps of the life cycle to augment readers' understanding of this topic often found in the science curriculum."

Christopher Columbus most likely wasn’t the person to discover the Americas. He wasn’t even the first European to do so! Despite that, his three trips to the Western Hemisphere led to many more European explorers heading in that direction. In this volume, readers familiar with Columbus’s travels on the Nina, Pinta, and Santa Maria can learn who Columbus was beyond his travels. Supported by full-color and historic images, interesting main content turns what readers think they know about the life of Columbus on its head while expounding on an important period in the history of the world.