Working with fractions and proportions is an important skill in mathematics because so many problems that we encounter in life require a working knowledge of proportional relationships. For example, if a Cook wants to enlarge a recipe to feed 25 people rather than 12, the original ingredients need to be 'scaled up' using proportional techniques. Many textbooks provided 'real world' examples for students using familiar examples drawn from every-day situations, such as the Cook's Dilemma we just mentioned, but there are many other areas where proportional relationships aid in understanding our physical world. This collection of activities is intended for students looking for additional challenges in the math and physical science curriculum in grades 3 through 6, but where the topics are drawn from astronomy and space science. This book 'Exploring Planetary Moons' introduces students to some of the most unusual places in our solar system that are not planets. Using simple proportional relationships and working with fractions, they will study the relative sizes of the larger moons in our solar system, and explore how temperatures change from place to place using the Celsius and Kelvin scales.