# Category: Number Theory

## Ordinals, Cardinals, Representation of Numbers in Language.

Quoted from:  Pi in the Sky, by John Barrow. Oxford University Press, 1992. p. 37-38 “English: one/first ; two/second ; three/third ; four/fourth French: un/premier ; deux/second or deuxième ;...

## Fibonacci Sequence

Definition A Fibonacci sequence is easily constructed:  Start with 0 and 1, and for each following number, add the previous two: 0, 1, 0+1=1, 1+1=2, 1+2=3, and so on. Here is...

## Prime Numbers

Prime numbers are the basic units of the system of numbers since every natural number is either a prime or can be expressed as a composite of prime numbers. Here...

## Perfect Numbers

Perfect numbers are gateways to the wonders of the mathematical world. Contemplating them, one realizes how small our human minds really are compared to the reality that surrounds us, and...

## The Number Pi

From Wikipedia: “π (sometimes written pi) is a mathematical constant that is the ratio of any circle’s circumference to its diameter. π is approximately equal to 3.14 in the usual...

## Fundamental Theorem of Arithmetic

The Fundamental Theorem of Arithmetic states that every positive integer can be written as a product of prime numbers in a unique way. The following description of the theorem and...

## Number Theory

The concept of “numbers” is itself very perplexing, and shows the evolution of mathematics from simple arithmetic,  to very complex operations.  Here is a brief overview of the types of...