Egypt · c. 850-c. 930

Abu Kamil

Abu Kamil was algebraist. He extended algebraic methods to problems with irrational quantities and systems of equations.

Documented historical record

Biographical and historical reference works document Abu Kamil’s role and the mathematical work summarized on this page.

Historical eraMedieval World
Math subjects
Grade bands

3-5, 6-8, 9-12, College

Profession trails

The person and the work

Biography

Abu Kamil was algebraist associated with Egypt. He extended algebraic methods to problems with irrational quantities and systems of equations.

Fibonacci later drew on traditions represented in Abu Kamil’s algebraic writings. Together, these contributions connect fractions, ratios, and percentages, algebra and functions, and geometry and measurement to the working problems, tools, and questions of the period.

Mathematical contribution

What this hero added or preserved

Core mathematical work

He extended algebraic methods to problems with irrational quantities and systems of equations.

Method, teaching, or application

Fibonacci later drew on traditions represented in Abu Kamil’s algebraic writings.

Why this matters

The larger lesson

Abu Kamil shows that mathematics grows through proof, calculation, observation, design, teaching, or careful records. The lasting lesson is that fractions, ratios, and percentages, algebra and functions, and geometry and measurement can turn a difficult question into a method another person can inspect and reuse.

Place the work in time

Timeline

  1. c. 850

    Life and working period

    Abu Kamil worked as algebraist in Egypt.

  2. Legacy

    Lasting mathematical connection

    Fibonacci later drew on traditions represented in Abu Kamil’s algebraic writings.

Key idea

Proportion preserves a relationship

Abu Kamil’s work connects quantities by ratio. Scaling both parts by the same factor keeps the relationship unchanged.

Example

The ratio 5:11 scaled by 5 becomes 25:55.

Try it yourself

Scale a ratio

Scale the ratio 5:11 by a factor of 5.

  1. Multiply the first term by the scale factor.
  2. Multiply the second term by the same factor.
  3. Confirm that both ratios simplify to the same value.
Show the answer

The scaled ratio is 25:55.

Math at work

Merchants and business owners use the same habits

Merchants and business owners use fractions, ratios, and percentages to plan, compare, test, or communicate decisions. Abu Kamil’s work provides a historical example of that connection.

Keep curiosity alive

A little-known fact

Fibonacci later drew on traditions represented in Abu Kamil’s algebraic writings.

Common misconception

Abu Kamil matters because of only one famous formula or anecdote.

What the evidence supports

The documented record is broader: He extended algebraic methods to problems with irrational quantities and systems of equations.

Keep exploring

Connected learning paths