Abacus and mental arithmetic means using the abacus for the teaching of mental arithmetic. Abacus is the tool used for the calculation of (+) plus, (-) minus, (*) multiplication and (/) division. When on uses an abacus, one has to follow certain rules and methods. When a person is familiar and skilful in the use of abacus, he will be able to calculate faster, Through feeling, perception and memory, one's brain will be train to work like the abacus and that is what its mean by abacus and mental arithmetic way of calculating.
Abacus and mental arithmetic method is the world's best method of learning calculating skill. Once you are good at the abacus and mental arithmetic way of calculating, you can calculate faster than an electronic calculator!