Hobbies And Interests
Sudoku
In this popular math puzzle, players must fill a grid with numbers so that each number appears once and only once in each row, column and group of boxes. Sudoku puzzle difficulty levels range from easy to expert, evil or wicked hard. You can find sudoku puzzles of all levels online at websudoku.com or dailysudoku.com. You can also find books full of sudoku puzzles at most bookstores.
KenKen
The kenken puzzle is similar to the more well-known sudoku puzzle, but has an added mathematical dimension. Players choose a grid size (4x4 to 9x9) and then must fill the grid's rows and columns without repeating any number. For example, if a player is working on a 9x9 grid, each row and column must contain the numbers 1 through 9 once and only once.
Unlike a sudoku puzzle, however, kenken puzzles also have highlighted groups of boxes with a particular mathematical operation and target number indicated. Players must ensure that, by performing the indicated mathematical operation, all the numbers in that group of boxes yield the target number. For example, if a group of three boxes has a "15x" inside it, the player can place the numbers 5, 3 and 1 inside the three boxes.
Numbers can repeat within box groups, but not within rows or columns of the larger puzzle. You can find daily 4x4, 5x5, 6x6, 7x7, 8x8 and 9x9 puzzles at kenken.com. The New York Times began printing the kenken puzzle in the spring of 2009.
Math Brain Teasers
Math brain teaser games present math problems within a story or riddle. For example, the brain teaser might ask you to determine how many handshakes would be required for every person in a group of 12 people to shake hands with every other person. Or you might have to determine the number of teams in a round robin tournament with only the number of games played as a clue. You can choose easy, medium and challenging level brain teasers at syvum.com, braingle.com and many other websites.