DS Kageyama Method Dennou Hanpuku: Masu x Masu Hyaku Masu Keisan

DS Kageyama Method Dennou Hanpuku: Masu x Masu Hyaku Masu Keisan is a Japanese educational puzzle game released for the Nintendo DS on 7 December 2006. Developed by Jupiter Corporation and published by Shogakukan, the title is designed to improve mathematical proficiency through repetition and speed.

The software is based on the "Kageyama Method," a learning technique developed by Professor Hideo Kageyama of Ritsumeikan University. It focuses on "Hundred Square Calculations" (Hyaku Masu Keisan), where players solve basic arithmetic problems in a 10x10 grid as quickly as possible.