Yes, Arithmancy is a real thing. It is a discipline in the real world that deals with assigning numerical values to words and phrases and then figuring out complex connections that form between these terms. These connections and patterns are studied based on the properties of numbers. Arithmancy is a major discipline under numerology. Unlike the magical discipline of Arithmancy taught at Hogwarts, its real-world counterpart does not delve into predicting the future based on the magical properties of numbers.