This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 9-12. It focuses on scales and numbers used when representing distances and sizes in the science of astronomy. This involves developing equations and using scientific notation for large numbers. The Earth, Sun, Milky Way galaxy and universe are all used to develop understanding of this concept. It includes objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.