Can you imagine a sloth as big as an elephant? How about a snake as long as a school bus? Megatherium and Titanoboa are two examples of animals who lived during the age of the dinosaurs. Learn about these and other lesser-known ancient creatures including Gigantopithecus, Liopleurodon, Megalodon, and Pteranodon as you develop your skills at reading and writing numbers. This nonfiction math reader builds literacy skills and math content knowledge, combining informational text, problem-solving, and real-world connections to help students explore math in a meaningful way. The Let's Explore Math sidebars feature clear charts and diagrams that make learning the concepts easy and fun. The Problem Solving activity enhances the learning experience and promotes mathematical reasoning, and the Math Talk section provides critical thinking questions to help facilitate rich discussions while developing students' speaking and listening skills. Text features include content-area vocabulary, dynamic images, a table of contents, a glossary, an index, and an answer key. Aligned to state and national standards, this high-interest title will engage students in reading and learning.