Thank you everyone for great info, both links are very helpful.
@Tom
Of course I agree with you that probably the best to learn abacus is to attend classes given by a good teacher.
I would like to ask you as a person, who teaches abacus to a younger children:
What requirements for a child to be able to attend Abacus Class?
Like you see, here on Brillkids forum we are very enthusiastic
, even parents of 2 year olds want to start it
But what skills a child has to master in order to be ready to start learning abacus?
Thank you in advance for your answer!