Aryabhata, an ancient known Indian mathematician who is believed to be from Kerala, has made the significant contribution to the mathematics and astronomy. Some of the most important work of Aryabhata includes approximation of pi, as, per Aryabhatiyam, the value comes to 3.1416. His other major work includes the sum of series of squares and cubes.
Varahamihira: Varahamihira used to live in Ujjain and his contribution in Trigonometry includes the sum of the square of sin and cos is one. He also defined the properties of zero and negative numbers.
Bhaskara I: Bhaskara is known for his approximation of sine function and first started Hindu decimal numbers.
Srinivasa Ramanujan: Important contribution of Ramanujan include inequalities in Algebra, partials sums, elliptical functions, etc.