The Montessori method offers activities that are understandable to the child, attractive to will power, and manipulative. The exercises of practical life offer opportunities to use various familiar objects such as buttons, brushes, dishes, pitchers, cleaning implements, and other things that the child recognizes from the home experience. The clear purpose of these materials stimulates the child's will to act with deliberate movements. Dr. Montessori's method also includes sensory exercises. These materials are designed to isolate physical properties such as dimension, color, shape, sound, weight, and texture. The child becomes consciously aware of the finer details of his or her environment. Dr. Montessori believed that at age three the child was ready to use mathematical concepts deliberately. Montessori materials help the child to consolidate mathematical abstractions into concrete form. The concept of zero and the place value of numbers are introduced so that children are ready to face the decimal world. Geometric and arithmetic concepts and their relationship become clear. The mathematical mind of the child becomes a math-exploring mind. Language materials, from sandpaper letters to grammatical activities, help the child become aware of the sounds that constitute our language. The child is then guided to write and read letters and words, the concrete symbols of the sounds we produce in speech. It is no doubt a multi-sensory experience.