Who were the first mathematicians? Probably the neanderthal that decided to count the food out equally. The fact is we just don’t know. It is very likely that we never will know as there is very little evidence to show that there was any understanding of the concept of numbers. Until early civilisations start to develop the practice how it begins is all guess work and conjecture. Civilisations come about after certain factors are met. Firstly, they need a supply of water and the chance to grow food. Then, when all external and military threats are removed people start to think, build and develop ideas. One of the first civilisations to do this was the Babylonians.
One of those ideas developed was mathematics. Since its first conception the Babylonians used the same system for two thousand years with no changes to it. For the first time, we actually have written evidence, most of it on clay tablets, of how they created and used it. This is unlike the Greek and, especially Egyptian mathematics, where every little evidence remains.
The evidence shows that they were able to use fractions and quadratic equations to help their construction process and businesses. It is just the same today with the Accountants Swindon based firm https://chippendaleandclark.com/services/accountants-swindon/, except that they don’t use clay tablets to record your tax returns.