Calvin Waffle is still 100% weird in the newest installment of David A. Adler’s laugh-out-loud chapter book series
 
Danny Cohen and his brainiac sidekick Calvin Waffle are back with a brand-new experiment!
Something is amiss in Danny and Calvin’s fourth-grade class when their loud, rule-enforcing teacher Mrs. Cakel suddenly transforms into a whole new person. Danny and Calvin decide the only way to find out what’s really going on is to spy on their personality-switching teacher. But spying soon leads to a greater mystery filled with dog chasing, jelly-injected donuts, peanut-butter-induced experiments, riddle mania, and more!!
 
Contributor Bio(s)
 
DAVID A. ADLER is the author of more than 200 books including the Cam Jansen mystery series, the Picture Book Biographies series, and the Bones beginning-to-read titles. After teaching mathematics for nine years, David wrote his first book in 1976. He was born in New York City, and currently lives in Woodmere, New York. Visit him at www.davidaadler.com.