KenKen is a puzzle whose solution requires a combination of logic

and simple arithmetic and combinatorial skills. The puzzles range

in difficulty from very simple to incredibly difficult. Students

who get hooked on the puzzle will find themselves practicing

addition, subtraction, multiplication and division facts. This

paper is divided into three main sections. The first section is a

sequence of one-step problems. We attempt here to include most of

the common ideas used in solving KenKen puzzles. The second

section solves a $6\times 6$ KenKen step by step, and includes

some mathematical notation that is needed only for problems that

are much harder than these, but nevertheless, may lay a foundation

for a formal approach to puzzles of this type. The final section

consists of Prize Problems.