Cotter AL Abacus, used with the RightStart™ Mathematics program, now available on your Android device! This abacus will teach, not calculate like the Japanese and Chinese abacus. Perfect for visual learners! This unique double-sided abacus is grouped in fives and tens for quick recognition of quantities. The second side of the abacus focuses on trading to the thousands. Learn the facts easily by * visualizing quantities, * minimizing counting, and * developing mental strategies. Those learning arithmetic with the Cotter AL Abacus have a better understanding of basic concepts and need less time to master arithmetic. Although children do enjoy using the abacus, it does not become a crutch. Stan, age 5, was asked how much is 11 plus 6. He replied, “17!” When he was asked how he knew, he replied with a grin, “I’ve got the abacus in my mind.” App has links to sample addition, subtraction, multiplication, and division lessons as well as detailed use information.