disadvantage of abacus
Size and weight
Abacus's advantage is improving mental calculations whereas its size and weight are its disadvantages.
China invented the abacus .
How did the abacus occur?
The Chinese abacus
An Abacus has beads and strings.
The First appearance of an abacus was in Sumeria around 2700 to 2300 BC.
the history about the abacus is that 3000 years ago the chinese invented the abacus. The abacus was made of wood parrelel rod and beads.
the Chinese invented the abacus
the invenor of the abacus is the invenor of me
Abacus is the first counting machine!