KenKen facts for kids

KenKen is a fun math and logic puzzle. It was created in 2004 by a Japanese math teacher named Tetsuya Miyamoto. He wanted to make a puzzle that could help train your brain without needing lots of instructions. The name "KenKen" comes from a Japanese word meaning "cleverness." You might also hear these puzzles called Calcudoku or Mathdoku.

How to Play KenKen

Just like in Sudoku, your goal in KenKen is to fill a grid with numbers.

• For a 4x4 grid, you use numbers 1 through 4.
• For a 5x5 grid, you use numbers 1 through 5, and so on.
• Each number can only appear once in any row.
• Each number can only appear once in any column.

KenKen puzzles come in different sizes, from small 3x3 grids to large 9x9 grids.

Understanding Cages

KenKen grids have bold-outlined sections called "cages." Each cage has a "target" number and a math operation (+, -, ×, or ÷) in its top-left corner.

• The numbers inside a cage must combine using that operation to reach the target number.
• For example, a cage with "6+" means the numbers inside it must add up to 6.
• Numbers can be repeated within a cage, but only if they are not in the same row or column.
• If a cage has only one cell, you just write the target number in that cell. This is like a "free space."

Some KenKen puzzles only use two cells for subtraction or division. This is because these operations can be tricky with more numbers. For example, if a cage says "1-" and you have choices like 2 and 3, you could use 2 and 3 (3-2=1) or 3 and 2 (3-2=1).

Example KenKen Puzzle

A typical KenKen problem.

Solution to the above problem.

Let's look at an example of a 6x6 KenKen puzzle. You need to fill the grid with numbers 1 through 6.

• Every row must have each digit (1-6) exactly once.
• Every column must have each digit (1-6) exactly once.
• Each bold-outlined cage must reach its target number using the given math operation.

You can use some tricks from Sudoku to help solve KenKen puzzles. Often, you'll list all possible number combinations for a cage and then remove options as you get more clues.

Here are some hints for the example puzzle:

• The "11+" cage in the first column can only be 5 and 6.
• The "2÷" cage in the top row could be 1 and 2, 2 and 4, or 3 and 6.
• The "20×" cage in the fourth column must be 4 and 5.
• The "6×" cage in the top right must use 1, 1, 2, and 3. Since the two 1s must be in different columns, the cell in row 1, column 5 must be a 1.

More Complex KenKen

Some KenKen puzzles are even harder! They might not tell you the math operation (+, -, ×, ÷). You have to figure that out too! Other puzzles might use more advanced math, like powers (exponentiation) or different number ranges, like including zero or negative numbers.

KenKen in Schools

KenKen is often used in classrooms to help students learn basic math and logic skills.

• In 2009, KenKen LLC started the KenKen Classroom (KKCR) Program.
• This program sends teachers weekly KenKen puzzles and other brain teasers.
• Today, over 25,000 teachers are part of the KKCR Program.
• KenKen also helps teachers set up KenKen clubs and tournaments at their schools.
• They work with groups like the National Council of Teachers of Mathematics (NCTM) to create apps that help students learn math and logic.

KenKen Tournaments

Since 2010, KenKen CEO Robert Fuhrer has organized yearly KenKen tournaments. These events are open to people of all ages and skill levels.

• In May 2015, KenKen partnered with IBM for an international tournament.
• In 2016, five students from India competed in the International Round in New York. Eight-year-old Gaurav Pandey won, beating older competitors!
• The United Arab Emirates also joined the KenKen International Championship in 2016, with over 6,000 students taking part.
• The KenKen International Championship is now held every year in New York.

Tournament Winners

Here are some of the past winners of the KenKen International Championship:

KenKen has grown a lot internationally. Many countries now hold their own national tournaments for students. Student winners from different age groups get to compete in the KenKen International Championship in New York.

• The Sigma division is for ages 14 and up.
• The Kappa division is for ages 11-14.
• The Delta division is for ages 11 and younger.

There are also divisions for adults and seniors (over 60).

See also

In Spanish: Kenken para niños