Professionally supervised! A brain activity book that will keep you engrossed in PHP until you're 100! 3 minutes a day brain training math puzzles 366 / 84929 1

●Country of production: Japan. A popular book containing questions supervised by neuroscientist Shinohara Kikunori. - 366 addictive math puzzles to train your brain. - Have fun training your brain with math puzzles such as inequality number puzzles, dot-to-dot puzzles, and shopping calculations! *Not sold at general bookstores.