3. The idea of zero as part of a system of numbers.
5. The creation of Arabic numerals
.
Explanation:
The<em> Navaratnas </em>or <em>Nine Jewels </em>were a group of nine scholars who produced advancements on many academic fields during the Gupta Dynasty. One of these scholars was Aryabhata, who is believed to have envisioned<u> the concept of zero as part of a numerical system.</u> He is know for also <u>working on the approximation for the long-form number Pi.</u>
Other scholars of the Golden Age helped create the first Indian numeral systems with a base of ten <u>(Arabic numerals).</u>