Indian Mathematics c11.5

c11.5

of the distance of an island from the shore, and the solution given occurs in Āryabhaṭa’s *Gaṇita* some two centuries later. The *Wu-t’sao* written before the 6th century appears to indicate some deterioration. It contains the erroneous rule for areas given by Brahmagupta and Mahāvīra. The arithmetic of *Chang-Ch’iu-chien* written in the 6th century contains a great deal of matter that may have been the basis of the later Indian works. Indeed the later Indian works seem to bear a much closer resemblance to Chang’s arithmetic than they do to any earlier Indian work.