Meet Addition they join numbers together! Addition is here to explain this core concept of mathematics to students through colorful and engaging examples. Readers will be introduced to counting, adding groups of tens, doubles, and matching. Activities at the back of the book encourage readers to test their knowledge. Along the way students will meet famous NASA mathematician Katherine Goble Johnson, who helped send the first space craft to space. A colorful timeline also introduces readers to the history of math. For more information on math strategies, check out other titles in the Building Blocks of Math series!