Professor Kageyama's Maths Training: The Hundred Cell Calculation Method(DS陰山メソッド「ます×ます百ます計算」DS Kageyama Method - Masu X Masu Hyaku Masu Keisan) , is a puzzle video game published by Nintendo and developed by Jupiter for the Nintendo DS handheld video game console. It was first released in Japan, and was later released in Europe and Australia. It was released in North America as Personal Trainer: Math in January 12, 2009. The game is part of both the Touch! Generations and Personal Trainer series.