- "Thanks for the book, Harry! I've been wanting that New Theory of Numerology for ages!"
- — Hermione Granger to Harry Potter [src]
New Theory of Numerology is a book that seems to be about Arithmancy, but is not a required text for the subject at Hogwarts School of Witchcraft and Wizardry. Harry Potter gave a copy to Hermione Granger for Christmas in 1995.
Appearances
| Arithmancy | ||
|---|---|---|
| Professors: Septima Vector | ||
| Known Arithmancers: Sage Bragnam · Lukas Karuzos · Chiara Lobosca's father · Bridget Wenlock | ||
| Textbooks: Numerology and Grammatica · New Theory of Numerology | ||
| Arithmancy at Hogwarts: Arithmancy (class) · Classroom 7A · Advanced Arithmancy Studies |