---
tag: VB4CMQ82C0
kind: concept
name: Egyptian fraction
aliases: [egyptian-fractions, eqyption-fraction, sum-of-fractions]
sources:
  - wikipedia: en:336349@r1373635052
    locator: Egyptian fraction
    note: adopted
    mention: wikipedia://en/336349
    sections: [Summary]
same_as:
  wikidata: Q1764362
  wikipedia: Egyptian fraction
inventory: [XCNSYB5Y5V]
---

## Summary

An **Egyptian fraction** is a finite sum of distinct unit fractions, such as

$$\frac{1}{2}+\frac{1}{3}+\frac{1}{16}.$$

That is, each fraction in the expression has a numerator equal to 1 and a denominator that is a positive [[integer|0C4JS9RF5M]], and all the denominators differ from each other. The value of an expression of this type is a positive [[rational number|0NCJ5WXN6Z]] $\tfrac{a}{b}$; for instance the Egyptian fraction above sums to $\tfrac{43}{48}$. Every positive rational number can be represented by an Egyptian fraction. Sums of this type, and similar sums also including $\tfrac{2}{3}$ and $\tfrac{3}{4}$ as summands, were used as a serious notation for rational numbers by the ancient Egyptians, and continued to be used by other civilizations into medieval times. In modern mathematical notation, Egyptian fractions have been superseded by vulgar fractions and decimal notation. However, Egyptian fractions continue to be an object of study in modern number theory and recreational mathematics, as well as in modern historical studies of ancient mathematics.