Egyptian fraction have been called "Horus-Eye fractions" after a theory (now discredited) that they were based on the parts of the Eye of Horus symbol. They were used in the Middle Kingdom in conjunction with the later notation for Egyptian fractions to subdivide a hekat, the primary ancient Egyptian volume measure for grain, bread, and other small quantities of volume, as described in the Akhmim Wooden Tablet. If any remainder was left after expressing a quantity in Eye of Horus fractions of a hekat, the remainder was written using the usual Egyptian fraction notation as multiples of a "ro", a unit equal
Horus name reaches back to the time of the Naqada II period at 3400 BC, and its development can be observed on objects from Naqada II to the 1st Dynasty. However, at the time of introduction, the serekhs of kings were yet anonymous. Later the name of the king was written beside the serekh or omitted completely. In many cases the serekh lacks the Horus falcon, and in other cases, such as the serekh of king Ka, the serekh seems to be held by Horus upside-down. During the middle and late Naqada III period (3200 - 3030 BC.), kings started to write