With summer almost upon us, I often have parents ask: how can they keep their kids practicing math facts over the summer without having a full out rebellion on their hands?! Well, KenKen is the answer! It is a brilliant math puzzle that helps build fluency in addition and subtraction facts, as well as multiplication and division facts; and kids love the challenge! With a range of difficulty levels, these puzzles appeal to age 6 – 106 and I can assure you that, if you’re not already, after this article, you and your children will be heavily addicted and KenKen crazy!

KenKen was invented in 2004 by a Japanese math instructor named Tetsuya Miyamoto. It was an instant international sensation and can now be found around the world, in classrooms, in apps, in puzzle books, and even in the New York Times (as well as other newspapers)!

Ken means wisdom in Japanese, so the name means wisdom squared! It is a numerical puzzle that increases in difficulty based on the size (ranging from 3X3, to 9X9) as well as the number of operations you choose (1-4).

Here’s what one looks like:

Source: https://krazydad.com/inkies/sfiles/INKY_3E_b002_4pp.pdf

Here are the basic rules:

1. You can only use the numbers 1, 2, 3 (for a 3X3).
2. Each row and each column must have one of each of those digits (1, 2, 3).
3. Each cage has a target number and states the operation you need to get there.
4. Order doesn’t matter.
5. Don’t guess – use mathematical reasoning to find the answers!

Here’s Rory (age 5) doing his first KenKen!

Here’s what the National Council of Teachers of Mathematics (NCTM) has to say about it:

KenKens “…encourage problem solving, reasoning, and mathematical communication, and they also promote important mathematical practices, such as perseverance and the ability to examine the reasonableness of a result.” Mathematics Teacher | Vol. 107, No. 5 • December 2013/January 2014

My take on it? If Sudoku is a logic puzzle, KenKen is a logic puzzle on drugs! Mental math drugs of course! Puzzlers are constantly working on their number sense and fluency because they are continually thinking of ways to compose numbers. For example, if the cage says 12X, how many ways can you multiply and get an answer of 12 using only the digits 1-6? If the cage says 2-, what numbers do I need to subtract to get an answer of 2? How many combinations are there?!

Are you ready to try it? Here is a link to the sources that I use! Now you too can go KenKen Crazy! Enjoy your summer!