Math = Love: Volume 3: Japanese Logic Puzzles for the Secondary Math Classroom

Saturday, August 6, 2016

Volume 3: Japanese Logic Puzzles for the Secondary Math Classroom

This is a continuation of a blog series about logic puzzles created by Naoki Inaba (creator of the area maze puzzle I blogged about here) that can be used in the secondary math classroom.  Actually, I see lots of applications to the elementary math classroom in today's set of puzzles, too.  Volume 1 of the puzzles can be found here and Volume 2 can be found here.

Naoki Inaba has published hundreds of logic puzzles for free on his website,  Of course, all of the puzzles are published in Japanese.  This is my attempt to make them more accessible to math teachers because they show potential for great applications in the math classroom.

I don't know Japanese, but I adore logic puzzles.  I especially love logic puzzles that have math-y applications and roots.  These definitely do.  You'll have to excuse my most likely poor translations.  If you see something I missed, please lave a comment!

Here are the rules:

1.  I'll post a picture of a puzzle and the solution.  The instructions are in Japanese.
2.  Determine the goal of the puzzle.
3.  Figure out how you could use it in your math classroom.
4.  Scroll down and see if your thoughts match mine!

(Puzzles 1-3 are found in Volume 1.  Puzzles 4-6 are found in Volume 2.)

Puzzle 7:

Inaba calls these "Shikaku" puzzles.  Google Translate changes the Japanese to "Square Cut."

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 I've actually written about shikaku puzzles before, but they looked much different than these.

These are basic area puzzles.  The numbers below each shape tell you to divide the shape up into rectangles with areas 3, 5, and 6.  You might have to remind students that squares also count as rectangles.  This always trips up at least a few kids.

This PDF file contains 42 of these puzzles which get progressively harder.  Solutions are posted here.

These would make a fun warm-up activity.  I think they're especially applicable when learning about prime and composite numbers.  In the above puzzle, there is only one way to make an area of 3.  It must be 3 x 1.  (Assuming 1 x 3 and 3 x 1 are the same, of course.)  There is also only one way to make the 5.  The 6, on the other hand, can be made as 6 x 1 or 2 x 3.

Puzzle 8:

Inaba calls these a "Zukei" puzzle.  Google Translate says the Japanese means "Looking for Graphic."

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Unless you can read Japanese, this puzzle is probably much trickier than the previous puzzles to figure out.  If you do Google Translate the text below the puzzle, you get "isosceles triangle."  Make sense now?

This is a PDF file of 42 puzzles for you to enjoy.  Solutions are here.  Because I'm nice and curious and hope to use this some day in the future if I ever teach geometry and I have a husband who is teaching geometry this year, I decided to go to the effort of translating each of the puzzle instructions.
These 42 puzzles cover the following geometry vocab words: square, rectangle, isosceles triangle, isosceles right triangle, right triangle, rhombus, trapezoid, and parallelogram.  Here's a Google Doc with the puzzle numbers and the corresponding shape that you are supposed to draw.

I think these puzzles are a must for any geometry class!  It would even be fun to have kids make some puzzles with other vocabulary words as an extension!

Puzzle 9:

Inaba calls these "Gemini" puzzles.  Google Translate Version: Gemini Formula

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 I was soooooooooo excited to run across these order of operation puzzles!  You have to insert parentheses and operations so that both equations are true.  And, to make things even trickier, you have to use the exact same parentheses and operations in BOTH equations!

Ready to do these with your students?  You'll find a PDF file of 42 of these puzzles here and solutions here.  I'm definitely incorporating these into my review chapter for Algebra 1 this year!


  1. Nice post! The Zukei puzzles remind me of this challenge that I posted on my blog a few years ago: -Daniel

  2. Regularly scheduled attempt at clarifying titles:

    "Shikaku" usually means "square", but more literally means "quadrilateral".

    I can't translate the second one. It's some kind of search. Probably a shape search.

    The character for "formula" can also mean "equation", and plurals aren't marked in Japanese. I would translate it as "Gemini Equations" or "Twin Equations".

  3. Hi! do you know Krazy dad ?
    There are a lot of different puzzles on this site
    My favorite is slintherlink
    Thank you for all your sharing

  4. Wow - absolutely love all of these. Last year of teaching & I find these ... at least I can spread the 'love' :-) Thanks for sharing the links.
    Hans in Australia