I've done Sudokus for a while. They are similar to crossword puzzles but with numbers instead of letters. You have to order the numbers so there are the digits 1-9 in each 3x3 square, each row, and each column. Sounds easy, but its rather complex. There are also Monster Sudokus that have digits 0-9 and add letters A-F. However, I've been more delighted with the Ken Ken puzzles. They not only have numbers (which I love) but also incorporate math skills (which I love). If you like math or simply enjoy puzzles, give them a try. This is the best selection I've found: You can do these on the computer or print them. Enjoy!