MSA Virtual Manipulative for Android
The base 10 models are bizarre. Hundreds are modeled as 3 dimensional (5x4x5). Tens are modeled as two dimensional. (2x5). 2 stacks of 5 tens make a hundred, and I don't see how 10 of these hundreds could be combined to make a thousands cube. Place value concepts are completely obscured. Even worse, the number balance does not balance even when the weights are equal.
by M####:
Pointless