Decimal system has been systematically employed in Hindu religion texts from the time of Vedas. Besides the primary numbers one to nine, expressed by the terms eka (1), dvi (2), tri (3), catur (4), pancha (5), sat (6), sapta (7), ashta (8), nava (9); their decimal terms are also mentioned in Hindu scriptures as dasa (10), vimsati (20), trimsat (30), catvarimsat (40), panchasat (50), sashti (60), saptati (70), asiti (80) and navati (90).

Terms which continue in series up to the power of thirteen
are also used and are named as sahasra (10^{3}), ayuta (10^{4}),
Niyuta (10^{5}), prayuta (10^{6}), Koti (10^{7}),
arbuda (10^{8}), nyarbuda (10^{9}), samudra (10^{10}), Madhya
(10^{11}), anta (10^{12}) and parardha (10^{13}). These
occur in the context of prayers for the bestowing benefits and blessings,
ten-fold, hundred-fold, thousand-fold, etc (Yajur Veda Vajasaneyi Samhita 17.2).

Apart from interim numbers in the decimal notation, like 11 (ekadasa), 12 (dwadasa), 21 (eka vimsati), 33 (trayastrimsat), etc., which imply the positional value of the digits mentioned above, prayers for multiple benefits were also made. Thus, the Marut gods were prayed for three times sixty for benefits (Rig Veda 8.96.8), and Indra was prayed for horses thrice seven times seventy (Rig Veda 8.46.26). This shows the popular, day-to-day use of the decimal system in ancient Hindu world, from the time of Vedas.

Some references to the written symbols of these decimal numbers are also found in the Vedas. Rig Veda 10.62.7 speaks of cows with the lobes of their ears “marked with 8” and pieces of gold with the symbol ‘8’ imprinted on them. Yajurveda Kathaka Samhita 13.10 states ashtamrdam hiranam.

The use of the decimal system was profuse during classical times, as seen from inscriptions and treatises on mathematics and astronomy. When the numbers are recorded, at times they are written using digits, and at other times they are spelt out. There has also been the tendency to use names of material objects (bhuta samkhya) to represent digits, like, for instance moon, earth and sky for 1, eyes, arms etc for 2, seasons for 6, week for 7, etc. The use of specific letters of the alphabets to represent the digits, called ka-ta-pa-ya-adi system was also popular, especially with mathematicians and astronomers.