Book excerpt: Ratios and proportions are good ways to break down and understand really big numbers, and the numbers don’t get any bigger than they do in outer space. This book brings young mathematicians on a space odyssey that will ultimately end with them gaining a greater understanding of how to solve word problems using ratios and proportions—and they might even learn a little science along the way. A tips section helps break down the problem-solving process into manageable steps designed to build confidence. These steps are repeated in every problem, helping reinforce the concepts and make them second nature.