Arithmancer and Arithmancy come from the Greek αριθμός (arithmos), meaning "number", and μαντεία (manteia), meaning "divination". Hence "Arithmancy" literally means "number divination".
Pythagoras and other philosophers of the time believed that because mathematical concepts were more "practical" (easier to regulate and classify) than physical ones, they had greater actuality.
Hermione Granger - famous high-ranking official in the Department of Magical Law Enforcement, who strongly contributed to Voldemort's downfall as she accompanied Harry Potter in the hunt for horcruxes; translated the Tales of Beedle the Bard into English from Runic.
Each number has Meaning and Power, Personality and Purpose. Students will learn the basics of Arithmancy, known today as Numerology. They will learn the mathematical equations necessary to calculate their special number as it pertains to their path in life and their personality traits, along with how to calculate these numbers for others.