Photography. History/Social Studies. Art. Blogs, Connections, Support, Information. Music & Video. Latin. Activities, trips, venues. Math for Chaz. Read_Write_Language. Science. Philosophy. Open source education. For Jamie. Gardening. Various Research. Fitness. Craft, cooking & entertaining. News. Work Resources. Graphic/Web design. Podcasts_listen. Natural world. How Numerology Works. In the world of Harry Potter, Hermione Granger's favorite subject is arithmancy.
The novels don't offer much detail, but they make it clear that arithmancy involves the magical properties of numbers. Hermione learns to use complex charts to perform numerical divination, or tell the future using numbers. In the real world, arithmancy is known as numerology. According to numerologists, everything in the world is dependent upon the mystical properties of numbers.