About maths all we can say is that ancient people who had from 4-3 b.c. developed a civilazation, had at least elementary knowledge about algebra and geometry, as many as they needed for their lives and their works-productions. This knowledge, it is reasonable for us to believe that in ancient civilazations existed in the same level as their own existance.
Greeks though, as they were seamen from the beginning, with increased knowledge and needs, overpassed quickly this level of development in geometry and found themselves really ahead in maths in realation to other civilazations-competitors. The pinnacle of this difference was the great discovery of the procedure of How To Prove The Geometrical Propositions. Truth is that the main characteristic of each ancient civilazation is not the accumulation of knowldege , in maths or any other science, over the years, but to discover a method to produce new “truths”, a method to disclosure the eternal laws that rule our world.
That’s because, while the empirical knowledge has been conquered after many years or been inserted from neighbors, the method to discover the unknown laws of nature and the secrets of maths, requires the development of the law of logic and the ability to accept axioms (proposals that can be proved by default), datas that only an upper civilazation has. That’s the reason why the discovery of that method considered to be the beginning of the science of geometry.
That is the biggest discovery and the work of ancient Greeks. This invention made geometry from the level of empirical knowledge for practical uses to the level of a science and laid the foundations of the theoritical research in all areas.