An Unusual Pattern

March 15, 2021
The four fourth grade Math Kids discover a cipher which leads them on a treasure hunt. Jordan and his friends, having defeated all the other fourth grade classes in their school, busily prep for the district math contest by solving challenging logic puzzles. But do they have a real-life puzzle to solve, as well? Stephanie finds strange symbols written in a library book. Justin immediately identifies the symbols as a pigpen cipher, and the Math Kids are off on an adventure. The pigpen cipher leads to another puzzle that seems to be nonsense blocks of letters. Each puzzle points to another, with both the ciphers and the math-contest practice presenting many opportunities for interested readers to try for a solution themselves. Frustratingly, know-it-all Justin, illustrated as White, has more of the puzzle-solving epiphanies than all of his friends put together; Stephanie, illustrated with brown skin, has almost none. (In the simple, semirealistic illustrations, Jordan also has brown skin, and Catherine presents White.) Nonetheless, 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. An appendix doesn't always clarify, but its explanations of cryptography and the Enigma Machine are stellar. Math, logic problems, and puzzles solvable by readers who want to try, all in a diverting chapter-book mystery. (Mystery. 8-11)

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