A calculation fun for BIG and SMALL, for YOUNG and OLD, for ADULTS and CHILDREN ! Calculate at different levels from the bottom up until you reach the top of the pyramid. From EASY to HARD, with plus and minus ! Special feature: The CHALLENGE MODE ! ---------------------------------- Each unit offers its own challenge mode. This means that you can collect points and break records in a prescribed time, and compare and share these with others in a leaderboard!
