// todo need optimize like in event.jsp. Add indexing or not indexing this page. Japanese Abacus (1 jan 1400 ano – 14 h 49 m, 1 jul 2019 ano) (Linha do tempo)

Japanese Abacus (1 jan 1400 ano – 14 h 49 m, 1 jul 2019 ano)

Descrição:

The Japanese Abacus can also be called a soroban. It is conceived from the ancient Chinese suanpan, which was imported to Japan in the 14th century. It has 4 beads at the bottom and one at the top and the number of rods in a soroban is always odd and never fewer than nine.