Editing Liber Abaci (section)

==Summary of sections==
The first section introduces the Hindu–Arabic numeral system, including its arithmetic and methods for converting between different representation systems.{{sfn|Sigler|2002|at=Chapters 1–7}} This section also includes the first known description of [[trial division]] for testing whether a number is [[composite number|composite]] and, if so, [[factorization|factoring]] it.{{r|mollin}}

The second section presents examples from commerce, such as conversions of [[currency]] and measurements, and calculations of [[Profit (accounting)|profit]] and [[interest]].{{sfn|Sigler|2002|at=Chapters 8–11}}

The third section discusses a number of mathematical problems; for instance, it includes the [[Chinese remainder theorem]], [[perfect number]]s and [[Mersenne prime]]s as well as formulas for [[arithmetic progression|arithmetic series]] and for [[square pyramidal number]]s. Another example in this chapter involves the growth of a population of rabbits, where the solution requires generating a numerical sequence.{{sfn|Sigler|2002|at=Chapter 12}} Although the resulting [[Fibonacci sequence]] dates back long before Leonardo,{{r|singh}} its inclusion in his book is why the sequence is named after him today.

The fourth section derives approximations, both numerical and geometrical, of [[irrational number]]s such as square roots.{{sfn|Sigler|2002|at=Chapters 13–14}}

The book also includes proofs in [[Euclidean geometry]].{{sfn|Sigler|2002|at=Chapter 15}} Fibonacci's method of solving algebraic equations shows the influence of the early 10th-century Egyptian mathematician [[Abū Kāmil Shujāʿ ibn Aslam]].{{r|ibn-aslam}}