Narwhals are often called the "e;unicorns of the sea."e; But these fascinating creatures are members of the whale family. Read all about narwhals as you practice addition. This nonfiction math book combines math and reading skills, and uses real-life examples of problem solving to teach subject-area content. The dynamic images, detailed sidebars, practice problems, and math diagrams make learning addition easy and fun. Text features include a table of contents, a glossary, an index, and captions to build vocabulary and increase understanding of math and reading concepts. An in-depth problem-solving section provides additional learning and practice opportunities. Engage students with this high-interest math book!