Kenken. Japanese brain training system. Book 4

Kenken is a Japanese brain training system that will help you improve memory, attention, logical thinking. Kenken was invented by a teacher from Yokogama Tetsuya Miyamoto. At first, he just wanted to help the students, to make sure that they were not bored in the lessons. But as a result, he invented an intellectual simulator for the brain that 3,000,000 people in Japan and the USA, Australia and Germany, India and Arab Emirates already love and know. Kenken translated from Japanese means "wisdom in the square". It is scientifically proven that Kenken develops cognitive abilities in young people and supports brain activity in people after 30 years. In this book you will find 300 very difficult puzzles: 150 puzzles 8 x 8 and 150 puzzles 9 x 9. Moreover, puzzles 1 - 150 are ordinary, and puzzles 151 - 300 - without signs of mathematical operations.
pump the brain!