It was not by accident or by try–and–error methods that ancient Egyptians had built tho­se magnificent mo­numents which started with the pyramids five thousand years ago. It is by profound scientific knowledge, a fact which has good evidence in the various mathe­matical papyri that were discovered, which reflect the deep knowledge in Mathematics, Geometry and calculations. When one investigates the way the ancient Egyptians mani­pu­lated their Mathematics, one gets surprised by the virtual simila­rity between the Mathe­matics that were used at the time of the pharaohs and the ones used by compu­ter systems today. We have only uncovered six principal papyri addressing Mathematics from the pha­raonic era until now: Reisner Pa­pyrus, the Moscow Mathematical Papyrus (MMP), the Kahūn Papyrus, the Egyptian Mat­he­matical Leather Roll (EMLR), the Rhind Mathematical Papyrus (RMP), and the Berlin Papy­rus. Each of the above sources contains a series of problems and their solutions. The most known papy­rus of them all is the Rhind Mathematical Pa­py­rus which is now on dis­play at the British Museum. It con­tains 87 problems in addition to a table for the de­com­position of two over odd numbers into unit frac­tions, which we are going to investigate in detail. We are also going to present briefly some hints con­cerning the inter–relations between Mathe­matics and the an­cient Egyptian religious symbols (mainly the apotropaic sound Eye of Horus).