Aryabhatta.
http://wiki.answers.com/Q/Who_invented_pie_maths

Pi was chosen as the letter to represent the number 3.141592. because the pi in Greek,
http://www.chacha.com/question/howwaspiinmath...

We know the Babylonians had quite advanced mathematics, because they left behind evidence on clay tablets, including some basic maths textbooks. Who might have had it before that
http://www.quora.com/SingaporeMathematics/Whoor...

Many think the Ancient Romans first used math, but there is an ongoing debate on whether math was invented or discovered.
http://www.kgbanswers.com/whoinventedmath/412583...
