Indian Epigraphy c15.t3.1

c15.t3.1

The celebrated astronomer Āryabhaṭa, who wrote his Āryabhaṭīya at Pāṭaliputra in the Kaliyuga year 3600 (499 A.D.), used a system of representing numbers by letters of the alphabet.¹ The 25 consonants from *ka* to *ma* indicated respectively the numerals 1 to 25. The 8 letters from *ya* to *ha* similarly indicated the numbers 30, 40, 50, 60, 70, 80, 90 and 100 respectively. The vowels *i*, *u*, *ṛ* and *ḷ* (short or long) and the diphthongs *e*, *ai*, *o* and *au* were added to the letters to indicate the multiplication of a number by 10² to 10¹⁶, i.e. the addition of two, four, six, eight, ten, twelve, fourteen and sixteen zeroes after a number indicated by a consonant. Thus *ga*=3, *gi*=300, *gu*=30000, *ya*=30, *yi*=3000, *yu*=300000, *ri*=4000, *giri* (or *gri*)=4300 (300+4000), etc.