KenKen: Design your own KenKen board by selecting the puzzle size, the operations, and the difficulty level.
Tower of Hanoi: Stack all the rings into one column with the widest on the bottom and the narrowest on the top.
4 x 4 Sudoku: Fill in the blanks with the numbers 1-4. Remember the numbers in each row, column, and 2x2 block cannot repeat.
6 x 6 Sudoku: Fill in the blanks with the numbers 1-6. Remember the numbers in each row, column, and 2x3 block cannot repeat.
9 x 9 Sudoku: Fill in the blanks with the numbers 1-9. Remember the numbers in each row, column, and 2x2 block cannot repeat.
Cat Dog Cat Dog Cat: Move the cats and dogs until the three cats and next to each other and the two dogs are next to each other.
Questions and Answers: Solve the problem, then check your answer. Click on "4th grade math" to try some of those problems.
River Crossing Problem: Help bring the wolf, goat and cabbage across the river safely.
Sheppard Math Games: This site features lots of games organized by topic.
Math Puzzles: This website has several different math challenges.