This is particularly for all those who use Soroban. I have developed my own Flash Anzan App (for Android) that has multiple features that help you boost your Mental Math skills rapidly !
Please try it out here: http://play.google.com/store/apps/details?id=com.flashanzan.app
I’m sure you would know that the only thing that slows us down is the “Extension Formulae” or “Families”.
Example: If we have 5 bead down, and we wish to do (lets say) +7, then we need to do: +2 -5 +10
With my app you can exclude such scenarios OR practice with a particular “+6”, “+7”, “+8”, “+9” family question, and improve on each of these by practicing them separately, and then later, all together
If you find it useful, please rate and share to help your friends or students as well !