As Mathematics teachers in Singapore, we have always heard about CPA (Concrete – Pictorial-Abstract) approach in teaching of mathematics. With the increasing popularity and the easily availability of virtual manipulative online, there is a need to include the manipulative approach. In the last sharing in TSG 18, Dr Lee shares about the CVPA approach (Concrete Virtual Pictorial Abstract). In his study, he has worked with some schools. Virtual manipulative can help to improve both the efficiency and effectiveness of the classroom instruction.
For more information, you can download his article from eJMT website