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Children's Fiction Mysteries & Detective Stories

An Encrypted Clue

by (author) David Cole

illustrated by Shannon O'Toole

Common Deer Press
Initial publish date
Apr 2021
Mysteries & Detective Stories, Diversity & Multicultural, School & Education, Friendship, Mathematics
  • Paperback / softback

    Publish Date
    Apr 2021
    List Price

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Where to buy it

Recommended Age, Grade, and Reading Levels

  • Age: 9 to 12
  • Grade: 3 to 6


To solve a decades-old mystery, The Math Kids need to crack a cipher. Can they do it in time?When Stephanie Lewis finds secret writing in the margin of an old book in the library, the Math Kids have a new puzzle to solve. But first, they must learn about codes and ciphers, and how to use their math skills to solve them. As one clue leads to another, the kids are drawn into the mysterious old house that overlooks the town. Is it really haunted like some townspeople say? And who is the man in the long beard who keeps showing up everywhere they go?But that's not their only problem. Unless they can find a solution, the math competition they've been training so hard for will be cancelled.Jordan, Stephanie, Justin, and Catherine will need to use all their problem-solving skills to figure out the clues before it’s too late. The Math Kids: An Encrypted Clue is the fourth adventure in David Cole's popular Math Kids series.

About the authors

David Cole's profile page

Shannon O'Toole is a Toronto based illustrator, painter and elementary school teacher. Her playful illustration work is inspired by the unique and humorous characters in her life. Aside from illustrating books for children, Shannon has exhibited her artwork in galleries across Ontario. When she is not drawing, Shannon can be found curled up with her dog, Edgar watching old movies. You can visit her online at or follow her on Instagram @shannonotooleart

Shannon O'Toole's profile page

Editorial Reviews

"In the entertaining middle grade mystery novel An Encrypted Clue, teamwork, brainwork, and generosity of spirit are fundamental to the solutions of more than just math problems."

Foreward Reviews, April 16, 2021

As with the other “Math Kids” books, author David Cole has left readers with a novel that will keep them wondering until the very end. The Math Kids: An Encrypted Clue is full of interesting fact and figures, problems and interesting historical notes. ... these books are as interesting for adults as they are for children. If you have not already found the value and the mysteries in mathematics, just read these novels to your children. Highly Recommended

CM Canadian Review of Materials, Volume XXVII / Issue 32 - April 23 / 2021

...the exciting conclusion is a true group solve, with the kids deciphering the overall metapuzzle, accomplishing as a team what they never could have solo. Math, logic problems, and puzzles solvable by readers who want to try, all in a diverting chapter-book mystery.

Kirkus Reviews, April 1, 2021

Other titles by David Cole

Other titles by Shannon O'Toole