LESSON 1: Kids Can KenKen
KENKEN RULES
1. Every square in the grid will contain one number.
" In a 3 x 3 puzzle, use the numbers 1 3.
" In a 4 x 4 puzzle, use the numbers 1 4.
2. Do not repeat numbers in any row or column.
3. A cage is a heavily outlined set of squares. Every cage has a target number in
the upper left corner. The numbers in the squares inside a cage must combine
to produce the target number. You must use the mathematical operation next to
the target number.
4. Cages with just one square should be filled in with the target number in the
top corner. (Hint: This is a good place to start solving the puzzle.)
Puzzle 1A Puzzle 1B
Puzzle 1C Puzzle 1D
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LESSON 1: Kids Can KenKen
OVERVIEW
Provide your students with fun, yet challenging, experiences with mathematics using KENKEN puzzles! This
lesson introduces KenKen and teaches students the basic rules and strategies for solving KenKen puzzles.
NCTM STANDARDS
Numbers and Operations:
Understand numbers, ways of representing numbers, relationships among numbers, and number
systems:
" Recognize equivalent representations for the same number and generate them by decomposing and
composing numbers;
" describe classes of numbers according to characteristics such as the nature of their factors;
Understand meanings of operations and how they relate to one another:
" understand various meanings of multiplication and division
" understand the effects of multiplying and dividing whole numbers
Compute fluently and make reasonable estimates:
" develop fluency in adding, subtracting, multiplying, and dividing whole numbers
" select appropriate methods and tools for computing with whole numbers [from among mental
computation, estimation, calculators, and paper and pencil according to the context and nature of
the computation] and use the selected method or tools
MATERIALS
Lesson 1 student worksheet with 4 KenKen puzzles.
PROCEDURE
1. Tell students that you have an answer, and they need to find the problem. Write 4 on the board. Ask
Using only 1, 2, and 3, what two numbers can you add to get this answer? (2+2 and 1+3) What if you
could use three numbers? (2+1+1)
2. Introduce KenKen puzzle 1A using a document projector or transparency. Ask students what they
notice about the grid. (Possible answers: There are three squares in each row and each column.
There are numbers in some of the squares. Some of the numbers have a + by them. Heavy black
lines mark one and two square groups.)
3. Tell students that this is a KenKen puzzle. Since it has three squares in each row and three squares
in each column, they can only use the numbers 1, 2, and 3 in the puzzle. Explain that each number
can only be used once in a column or row.
4. Point out the heavy black lines around the first two squares in the first row. Say: The heavy black
lines around these two squares show that these squares go together. This is called a cage. Have
students identify the other cages in the puzzle. (top two squares in right column; 2 squares in last
row on right; etc.)
5. Ask students to look for any cages that have only one square. (center of the grid) Say: This cage has
only one square, so the number in the box tells us what to write. Write 1 in the middle square.
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6. Say: The cage in the first row has a 3 and a plus symbol. This means that the two numbers in this cage
must add up to 3. What numbers might we use? (1 and 2; If students mention 3 and 0, point out that
they can only use 1, 2, and 3 to solve this puzzle.) If we can only use a number once in each row,
which number should I write in the right square in this cage? Why? (2, because 1 is already used in
the middle column) Write 2 in the top middle square and 1 in the top left square to complete the
cage.
7. Continue solving the puzzle by asking students to determine possible combinations for each cage.
Encourage students to discuss how they figured out which number should go in each square.
8. Have pairs of students work together to solve puzzle 1B. Ask them to share their strategies with the
class as they check their work.
CHALLENGE!
Encourage students to work alone or in pairs to solve the 4x4 KenKen puzzles  1C and 1D. Point out
that they will use the numbers 1, 2, 3, and 4 to solve these puzzles. Remind students to check the
symbols next to the target numbers in each cage to determine whether to add or subtract to find the
correct combinations for each cage. Encourage students to discuss the puzzles with the class: What
strategies worked best? How were 4x4 puzzles different from 3x3 puzzles? How did they like the mixture of
operations? What was the biggest challenge?
Puzzle 1A Puzzle 1B
Puzzle 1C Puzzle 1D
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