Mathematics in Ancient and Medieval India c5.s7.8

c5.s7.8

(A) *Word-numerals* : The word-numerals were based on a decimal scale of notation namely *eka*, *daśa*, *śata*, *sahasra*......upto 12 places from the time of *Saṃhitas* (1500 B.C.).² A large number like, *ṣaṣṭhīm sahasrā sapta śatāni navatim nava* ( 60, 799 ) was expressed by placing the word numerals of higher order to be followed by one of lower order in the scale. This successive placing of, *sahasra*, *śata*, *daśa*, *eka* for the expression of a large number in left to right order of gradually decreasing values obviously shows that the idea of decimal place-value was implied.¹ The scale is undoubtedly more convenient than the Babylonian sexagesimal scale. The *Śatapatha Brāhmaṇa*, *Taittirīya Brāhmaṇa*, *Chāndogya Upaniṣad*, *Vedāṅga Jyotiṣa* etc. had similar uses of numerals. The idea of decimal place-value developed when the decimal scale was associated with the value of the places in a right to left order (or left to right) in the scale with the introduction of symbol for zero. That means, the symbols or word numerals took values × 1, × 10, × 100.........when placed in 1st, 2nd, 3rd places......respectively. From the beginning of the Christian era, the word-numerals with their various synonyms began to be used to avoid repetition of the same word and to keep rythm of ślokas.