“Elementary (Logic), my dear Watson…”

I married into a family of mystery fanatics. Sherlock Holmes. Agatha Christie. Family viewing of Murder She Wrote and Masterpiece Mystery each week. My husband grew up cracking codes and solving cases from Agent Arthur books in the backseat on long car trips. They even do Murder Mystery puzzles on vacation (still). It is no wonder that he now makes games and puzzles for a living. Fortunately, I too enjoy the mystery genre and am even more of a fan of puzzles of all kinds. You might not be surprised to learn that I particularly enjoy word puzzles (acrostics, anagrams, word squares, oh my!) but I also have a special fondness for a sentimental favorite—Logic Grid Puzzles.

My mother is a math teacher so we often were her test subjects for games and problems she used in class. Logic Grid Puzzles were a frequent fast finisher activity and are such a satisfying way to solve a tricky problem. Fast forward many years later to my own classroom where Common Core standards require close reading of texts in order to dig deeper into what the author really means—a difficult skill for many of my ELL students who have a tough time moving past a literal understanding of what is stated in a text. Kids need help in more lateral thinking, making some leaps based on evidence? Logic Grid Puzzles came right back to mind.

Logic Grid Puzzles are a simple way to show kids how to draw conclusions based on evidence that is stated, or unstated. Puzzles use a grid and simple Xs and Os to help students keep track of what they know or have figured out about a puzzle so far.  In a puzzle that asks you to figure out who bought what animal and for how much, a clue might read, “Doug bought a horse, but he didn’t pay $100.” On the grid you can mark an 0 where Doug and the horse intersect and cross off both $100 for Doug and Horse for Max and Tom. We also can cross off Cat and Dog for Doug since we know he has a horse.

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These leaps of logic seem simple enough, but for a student who relies on stated fact, knowing to cross off Cat and Dog because Doug is getting a Horse takes some inferring skills. Once a student completes a few of these kinds of puzzles however, it becomes much easier to follow this pattern in filling in the grid. These inferences become natural because they know that when they are given such a specific piece of information it negates all others in that category.

The key to using these kinds of games in reading practice is naming aloud what you are doing. This practice of using evidence to draw conclusions can be transferable to reading other texts if you repeatedly remind your student: “Wow! The clue said one thing and you used that information to figure out a lot more!” “Because we know this, now we can figure that out too!” “Even though the writer didn’t tell us who bought the Dog, we figured it out using the clues!” These phrases can be used alongside a reading passage that requires some similar leaps of thinking so students continue to see that using evidence from a text plus our own thinking is what a makes an inference!

If you’d like to use Logic Grids in your classroom (or at home!!!) check out these puzzles from my teacherspayteachers store or download an app my husband made so we could use these on iPads at school!


How could anyone resist reading practice disguised as a game? It’s a mystery to me…

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