There is lot of classification in mathematics, for eg Hipparchus is the founder of trigonometry, so each and every classification has different one so which u wanna know? 
Well in reality there is no actual founder of math . but there are discoverers even though they were discoverers doesn't mean that they thought about their concept first. but anyway i'll name some of that are well known .
sir issac newton discovered calculus by thinking of functions appraching zero .even though he might have recorded calculus because i'll bet there were people in the human race that pondered the same idea that newton wrote in his principle mathmatica .algebra was discovered by a muslim scholar in around the peak of the islamic era.he once again did not discovered algebra for the first time because i'll bet you that before him there were people who pondered the same idea he calculus teacher taught herself calculus .that means she never looked at a textbook.she found by herself the pattern of calculus and worked off her own proofs and theorems .then once she reached as far as she could think.she finally consulted the calculus textbook.and learned the standard way as we all today learn . so if she lived in the time period of newton ahe would have been the actual person who discovered calculus .
math is nothing but proof and theorems .as long as proof and theorems makes sense then they are accepted as math .
i hope u understand.