9 books in series

Sir Cumference

Sir Cumference is a 9-book series with 9 primary works first released in 1997 with contributions by Cindy Neuschwander.

Sir Cumference and the First Round Table: A Math Adventure
Sir Cumference and the Dragon of Pi: A Math Adventure
Sir Cumference and the Great Knight of Angleland
Sir Cumference and the Sword in the Cone
Sir Cumference and the Isle of Immeter
Sir Cumference and All the King's Tens: A Math Adventure by Cindy Neuschwander (2010) Paperback
Sir Cumference and the Viking's Map
Sir Cumference and the Off-the-Charts Dessert
Sir Cumference and the Roundabout Battle