The following have been voted the top 10 websites for helping kids/parents/teachers use math techniques. You can find kenken in many of them. Thanks to Sylvan Learning Center
1) www.mathforum.com. This online community includes teachers, students, researchers, parents and educators who have an interest in math and math education. The site includes Ask Dr. Math, Problems of the Week, discussion groups and much more.
2) www.AAAmath.com. Customized by grade level and topic, AAA Math features explanations of various mathematical topics, practice problems and fun, challenging games.
3) www.coolmath.com. This fully interactive site and allows the user to sharpen basic math skills, play games and explore new math concepts.
4) www.figurethis.org. Created by the National Council of Teachers of Mathematics, this site helps families enjoy mathematics outside school through a series of fun and engaging challenges.
5) www.mathcats.com. Math Cats provides playful explorations of important math concepts through games, crafts and interactive projects. Includes a magic chalkboard and an art gallery.
6) www.easymaths.org. This South African Community website for teachers, parents and students is complete with lessons, tests, exams, worksheets, study skills and much more.
7) www.bbc.co.uk/education/megamaths/tables.html. This lively, interactive Web site, based on the popular BBC Schools Television series “Megamaths,” is for practicing and testing times tables.
8) www.mathleague.com. The Math League, designed for students in fourth grade through high school, specializes in math contests, books and computer software. The “Help Facility” is handy reference guide for math topics complete with examples, definitions and explanations.
9) www.fleetkids.com. FleetKids games teach elementary children several different aspect of money management. Games include Windfall, where a child can run an imaginary business and BuyLo/SellHi, where children can play the stock market. Students can sign up as an individual or as part of an elementary school team.
10) www.funbrain.com/numbers.html. This site includes 17 original games based on soccer, car racing and much more Other games include Math Baseball, where a child can score runs with correct answers and Operation Order, where students can build pyramids with their knowledge of algebra.