Naoki Inaba has published hundreds of logic puzzles for free on his website, inabapuzzle.com. 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. Puzzles 7-9 are found in Volume 3.)

## Puzzle 10:

Inaba's file name for these puzzles is "Dokoeq." Google Translate changes the Japanese to "Where Kana Calculation."

Image Source: http://inabapuzzle.com/study/dokoeq_q.pdf |

These are much more elementary-looking puzzles, but I think they'd still make great warm-ups or brain-breaks in the secondary classroom.

The numbers and arrows tell you that there is a specific number in that row or column. In the case of the five, it's clear what number MUST go in that box. With the three, we know it can't go in the top box because 3 + 5 does not equal a 2-digit number. Therefore, it must go in the bottom box. There's so much math and logic going on. I love it!

## Puzzle 11:

Inaba calls this puzzle "Zero." Google Translate changes the Japanese to "Zero Zero Formula."

Image Source: http://inabapuzzle.com/study/zero_q.pdf |

This PDF file contains 49 of these puzzles and gets progressively harder. Solutions are here.

##

Puzzle 12:

Inaba calls this a "Step" puzzle. Google Translate switches the Japanese to "Stairs of the Numbers."

Each line represents a different arithmetic sequence. 1, 2, 3 is going up by 1. 1, 3, 5 is going up by 2. And, 2, 5, 8 is going up by 3. The fact that they are overlapping just makes it even more fun. :)

This PDF file contains 42 of these puzzles with solutions posted here.

In Oklahoma, arithmetic sequences are now an Algebra 1 standard instead of an Algebra 2 standard. I'll definitely use some of these puzzles as an intro into sequences.

Just for completion, one final clarification of the titles:

ReplyDeleteThe "kana" is just a question mark. It means "where's the equation?" Google is accurate on the second and third puzzles, though you can probably figure out that "number stairs" is a more normal translation of the third.

Note that there may be multiple possible solutions to the third puzzle.