History of Hindu Mathematics: A Source Book v1.c7.s4.36

v1.c7.s4.36

The numbers 19, 29, 39, 49, etc., offer us instances of the use of the *subtractive* principle in the spoken language. In Vedic times we find the use² of the terms *ekânna-viṁśati* (one-less-twenty) and *ekânna-catvâriṁśat* (one-less-forty) for nineteen and thirty-nine respectively. In later times (Sûtra period) the *ekânna* was changed to *ekona*, and occasionally even the prefix *eka* was deleted and we have *ûna-vimśati*, *ûna-trimśat*, etc.—forms which are used upto the present day. The alternative expressions *nava-daśa* (nine-ten), *nava-vimśati* (nine-twenty), etc., were also sometimes used.¹