Rightstart Math is a Montessori-based math program for elementary and middle school age children. It uses games and an abacus to teach in a method that is both kinesthetic and visual.
The manipulatives are an extra cost that can add up, but they will be used for many years and add significant value to the program.
It can only really be used in a cooperative setting if all children are using the same curriculum for the same year. However, the games are a useful enrichment tool that can cover multiple years for all styles of learning.