The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Math Galaxy:
Math Galaxy Decimals, Proportions, %, is like having an interactive textbook, with explanations, practice, and games that cover decimals, ratios and proportions, percents, measurement and data analysis, including length, area, volume, weight, graphs, frequency tables, mean (average) & median, stem-and-leaf plots, and box-and-whisker plots.The concepts are presented in bite-size pieces with an unlimited number of practice problems, with numbers chosen randomly.By solving problems students earn robots to use in a maze game called the Labyrinth.