The Dot Exercise provides practice in decimal system addition. Through use, the child further explores column addition and experiences the mechanism of ‘carrying.’ The Dot Exercise grid is printed on a whiteboard upon which the child writes with water based pens of 2 different colors. 2 pens included. Item Number: 005050 The printed notes of this Montessori presentation from our CME Teacher Preparation Course are available for purchase from this webpage. Please search for: The Dot Game.