Page:A history of Japanese mathematics (IA historyofjapanes00smitiala).pdf/35

Rh The date of the introduction of the rods into Japan is unknown, but at any rate from the time of the Empress Suiko (593—628 A. D.) the chikusaku (bamboo rods) were used. These were thin round sticks about 2 mm. in diameter and 12 cm. in length, but because of their liability to roll they were in due time replaced by the sangi pieces, square prisms about 7 mm. thick and 5 cm. long. (Fig. 5.)

When this transition took place is unknown nor is it material since the methods of using the two were the same.

The method of representing the numbers by means of the sangi was the same as the one already described as having long been used by the Chinese. The units, hundreds, ten