Has anyone out there used Number Talks: Helping Children Build Mental Math and Computation Strategies by Sherry Parrish or Learning to Think Mathematically with the Rekenrek?
Here is a Rekenrek. Looks like an abacus.
I am trying to figure out how to approach math "fluency" and these have been suggested, but the price is NOT right for me.
I haven't had much success with Otter Creek Math. Any ideas would be appreciated.