Wikipedia diagram by David Eppstein :

This is an updated text from 2002, called “Finding the Perfect Ruler”

Any number with limited “significant digits” can be and should be expressed as a product of positive and negative powers of the prime numbers that make it up. For example, 23.413 and 234130 can both be expressed as an integer, 23413, multiplied or divided by powers of ten.

**What Primes are**

**Primes** are unique and any number must be prime itself or be the product of more than one prime. Having no factors, prime numbers are **odd** and cannot be **even** since the number 2 creates all the even numbers, meaning half of the ordinals are not prime once **two**, the first “number” as such, emerges.

Each number can divide one (or any other number) into that number of parts. In the case of **three** (fraction 1/3) only one in three higher ordinal numbers (every third after three) will have three in it and hence yield an integer when three divides it.

**Four** is the first repetition of **two** (fraction ½) but also the first square number, which introduces the first compound number, the geometry of **squares** and the notion of **area**.

**Ancient World Maths and Written Language**

The products of 2 and 3 give 6, 12, etc., and the perfect **sexagesimal** like 60, 360 were combined with 2 and 5, i.e. 10, to create the base 60, with 59 symbols and early ancient arithmetic, in the bronze age that followed the megalithic and Neolithic periods.

Continue reading “Working with Prime Numbers”