Numerology and Grammatica

Numerology and Grammatica is an Arithmancy textbook used by Third year students at Hogwarts School of Witchcraft and Wizardry. Hermione Granger briefly misplaced her copy in 1994.

In 1997, Hermione considered this book as she was sorting supplies for their mission to find Voldemort's Horcruxes. Apparently, it was useless for what they were about to set out and do, so she decided to leave the book behind.

Behind the scenes

 * In the Harry Potter films, this book appears to actually be two separate, though visually similar, books: Numerology, by L. Wakefield; and Grammatica, by M. Carneiro.

Appearances

 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Deathly Hallows