Can anyone recommend resources for learning to use an abacus? Physical media preferred, but websites are also ok. English language please.
I have a Chinese-style (suanpan) and two Japanese-style (soroban) abacuses. I'm especially interested in advanced techniques that you would need if you were replacing your calculator with an abacus.
Are there other abacus types useful for specific calculations?
I find the Lee Kai-chen Abacus fascinating: http://totton.idirect.com/abacus/Lee/