A kid's detective agency uses mathematics to solve problems.

"With the discovery of Mrs. Magpie's Manual of Magic for Mathematical Minds, Lulu and Elizabeth embark on an exciting journey to a realm inspired by Lewis Carroll's poetry. The twins must use ingenuity and sagacity to solve classic logic puzzles that promise to uncover the book's secrets and earn them The Vorpal Blade. In this interactive novel, the reader is invited to play along with the two heroines on their grand math adventure."--back cover.

It's Christmas Eve in Ravensburg, and the town is bursting with anticipation for its oldest Christmas tradition. The annual opening of Douglas and Son's Toy Store, home of the greatest toys in the world, is finally here. But this is no ordinary Christmas Eve, and the surprise that awaits them is beyond any of their wildest imaginations: a surprise that threatens to ruin Christmas! Stanley, Charlotte, Gertie and Felix call in a little backup, but will...

On Sunday, Mr. Jenkins welcomes one pig into his pool, and as the week progresses, the number of pigs in his pool increases exponentially, too.

Members of the Critter Club are all excited about their summer plans until Liz learns that, instead of taking an art class, she will have to be in summer school to improve her math skills, but a fun teacher, a classroom pet, support from her friends, and advice from her brother might get her through.