Egyptian Fractions Calculator

Convert proper fractions to Egyptian fraction expansions using greedy, pairing, or splitting algorithms

Convert Fraction to Egyptian Form

Top number of the fraction

Bottom number of the fraction

Method for decomposition

Example: Converting 6/7

Greedy Algorithm Example

Step 1: 6/7 = 1/⌈7/6⌉ + remainder

Step 2: ⌈7/6⌉ = ⌈1.167⌉ = 2

Step 3: 6/7 = 1/2 + (6×2 - 7)/(7×2) = 1/2 + 5/14

Step 4: 5/14 = 1/⌈14/5⌉ + remainder = 1/3 + 1/42

Result: 6/7 = 1/2 + 1/3 + 1/42

Algorithm Comparison

Greedy Algorithm

Most efficient, shortest expansions

✓ Recommended for most cases

Pairing Algorithm

Resolves conflicts by pairing identical fractions

✓ Educational value

Splitting Algorithm

Creates many terms quickly

⚠️ Limited to small numerators

Historical Context

📜

Used in ancient Egypt (3200 BC+)

🔢

Found in the Rhind Papyrus (81 of 87 problems)

🍞

Used for dividing bread among workers

👨‍💼

Fibonacci proved every fraction has an expansion

Understanding Egyptian Fractions

What are Egyptian Fractions?

An Egyptian fraction is a representation of a proper fraction (numerator < denominator) as a sum of distinct unit fractions (fractions with numerator = 1). For example: 3/4 = 1/2 + 1/4.

Key Properties

  • All unit fractions must be distinct (no repetition)
  • Every proper fraction has an Egyptian expansion
  • Expansions are not unique (multiple representations exist)
  • Used for practical division problems in ancient times

Greedy Algorithm Formula

x/y = 1/⌈y/x⌉ + (remainder)

  • ⌈y/x⌉: Ceiling function (round up)
  • Remainder: (x×⌈y/x⌉ - y) / (y×⌈y/x⌉)
  • Repeat: Apply to remainder until numerator = 1

Example: 4/5 = 1/2 + 1/4 + 1/20

Modern Applications

  • • Equal division problems
  • • Mathematical education
  • • Computer science algorithms
  • • Number theory research

Special Cases

  • • 2/3 had its own Egyptian symbol
  • • 3/4 also had a special symbol
  • • 1/2 was written with unique notation
  • • These didn't need unit fraction expansion

Mathematical Interest

  • • Proof of finite termination (Fibonacci)
  • • Optimization problems
  • • Continued fraction connections
  • • Algorithmic complexity studies