MATH
The newest Magic Tree House Book is Dogs In The Dead Of Night which is coming out in August 2011.---- As of for June 2011 the day I am writing this answer, the newest Magic Tree House book is book #45-A Crazy Day With Cobras.
she is still writing and her newest book comes out fall 2010
It is the Magic Tree House 41th book.
i believe in the second book it was a tree tap for the rubber trees but correct me if i am wrong
The 20th book in the Magic Tree House series is Dingoes at Dinnertime.
The highest magic tree house book is Book # 55, "Night of the Ninth Dragon."
The 3rd book in the Magic Tree House series is "Magic Tree House #3: Mummies in the Morning".
Magic Tree House book #39 is called "Dark Day in the Deep Sea".
The 44th Magic Tree House book is A Ghost Tale for Christmas Time and it was published in 2010.
The very last Magic Tree House book in the series is "Hurricane Heroes in Texas" which is book number 135.
It is a book that has a brother and sister travel to different times via Morgan Le Fay's magic tree house (morgan is not evil in this book).
Yes, there is a book 46 in the Magic Tree House it's name is Dogs In The Dead Of Night.