Q:

Soroban Abacus - how to memorise?

I saw a video where Indian kids where fiddling fingers in the air and working out big sums. WOW I thought.
I researched loads and have figured out that it's all based on using the Soroban Abacus (a Japanese abacus if you don't know).
I got a little program on my Android phone and have mastered using the Soroban Abacus.
BUT the bit I am missing is how they keep the abacus mentally pictured in their heads??
I'm sure I could try to remember myself and keep in my head - but I'm assuming there is some methodology behind how the kids do it.
These little kids seemed to be on over drive adding about 10 2 digit numbers in lightning speed. Old kids did even better.
Anyone know?
Thanks
Omar

A:

Yes, I learned this method when I was 6 years old. You have to first practice with a real abacus, and once you practice enough, you will eventually to be able to do it in your head. I can do multiplication like $563*471$ in my head, but many people who are better than me can do even harder problems.

