Our Moon has been admired for thousands of years, and because of this is one of the most familiar astronomical objects to children of all ages. Its cyclical phase changes from full Moon to new Moon and back over the course of 28 days, has been an important source of time-keeping for many different civilizations. The dramatic landings of Apollo astronauts on the Moon starting in 1969 have made the Moon an almost common-place extension of humanities 'neighborhood' in space - one to which we may return in the coming decades. The activities in this book are designed to give students in grades 3-5 an opportunity to discover our Moon- Earth's only natural satellite and use mathematical concepts to understand size and proportion This book was created so that younger students can explore the lunar surface through the many photographic resources that have been collected by NASA over the years. Students should be encouraged to look at each photograph in detail and study the changing appearance of the moon as we move closer to its surface. They should be encouraged to ask many questions about the details and features that they see, and how to move from one picture to another as the scale of the images change. They may also make a game of this process along the lines of 'I Spy'. This book focuses on 'scale and proportion' as mathematical topics. A number of hands-on activities are also provided to allow students to create and explore scale-models for spacecraft and lunar craters.