Ancient Egyptians developed mathematics to solve practical problems. They used mathematics to measure time, find the height of the Nile flood each year, calculate areas of land, count money, and determine taxes. Math was necessary for the complex engineering used to build the pyramids. Simple mathematics were used by shop keepers and cooks, while more complex mathematics were practiced by the priests and priestesses, overseers in charge of workers, masons, surveyors, engineers, and tax collectors.
The ancient Egyptians worked from a base of 10 and used hieroglyphic symbols only for the number 1 and for numbers that are powers of 10, such as 100 and 1,000. Symbols were repeated to show multiples of that value, much like Roman Numerals.
Texts written to record or teach a mathematical procedure are an important source of information about Egyptian mathematics. Some papyrus fragments contain table texts, which were tables used to reckon fractions or to make conversions of weights or measures. The Rhind papyrus, a fifteen-foot-long scroll written around 1660 BC, records dozens of mathematical questions and their answers. Most of what is known about ancient Egyptian mathematics was revealed by this scroll. It shows that Egyptians had mastered arithmetic and had developed formulas for solving problems with up to two unknowns. They also had simple geometrical and arithmetical progressions using fractions.
Egyptians knew addition and subtraction. They could multiply and divide, but used a system of doubling to find answers. They were familiar with roots and square roots. They could find the area of a triangle and a circle, for which they used 3.16, very close to the 3.1416 of pi. The Egyptians knew rudimentary geometry. They calculated that a triangle whose sides were in the ratio of 3:4:5 had a right angle opposite the hypotenuse and possibly knew the principle of the Pythagorean Theorem. The ancient Egyptians also could plot an arch.
In the Greco-Roman era, Egyptians learned the geometry of Pythagoras, Plato, and Euclid. The concept of zero was introduced to the Egyptians by the Arabs during the Islamic period.