1) Israeli invention 
Hidato (חידאתו, originating from the Hebrew word Hida = Riddle), also known as `Hidoku`, is a logic puzzle game invented by Dr. Gyora Benedek, an Israeli mathematician. The goal of Hidato is to fill the grid with consecutive numbers that connect horizontally, vertically, or diagonally. Numbrix puzzles, created by Marilyn Vos Savant, are si.....