Matt, Bibi, and their dog Riley crawled through the tiny opening first. FWUMP! A secret door suddenly closed behind them . . . The Zills family is summoned to Egypt to help find the hidden burial chamber of an ancient pharaoh. But when Matt and Bibi get trapped in the pharaoh's pyramid, they stumble upon an even bigger mystery. With only each other, their dog Riley, and the geometric hieroglyphics on the walls to help them, the twins must use their math skills to locate the burial chamber--and the way out. Luckily, Matt and Bibi know their stuff when it comes to geometric solids, and so will the readers of this adventure in math!About the Author: Cindy Neuschwander is the author of the Sir Cumference series, and she is also a third-grade teacher. Although she has never been trapped inside a pyramid, she has explored some in Egypt. Ms. Neuschwander lives with her family in Northern California. Bryan Langdo is the illustrator of several books for young readers. He is a big fan of mummy movies and lives in New Jersey with his wife. Together, Ms. Neuschwander and Mr. Lango have created three Adventures in Math picture books for Henry Holt. Patterns in Peru was published in Spring 2007, and Pastry School in Paris will be out in Spring 2009.