How do we know Arithmancy is actually a job? I was under the impression it simply referred to one who studies and practises Arithmancy. Green Zubat 14:48, August 7, 2011 (UTC)

"Arithmancer" is a person whose job concerns the study of Arithmancy, just like "mathematician" denotes a person whose occupation is the study of Maths. By the way, is the word "Arithmancer" actually used in the books? --  Seth Cooper  owl post! 15:00, August 7, 2011 (UTC)
It was used in Bridget Wenlock's "Wizard of the Month" description on JKR's official site.[1] Starstuff (Owl me!) 06:55, August 8, 2011 (UTC)