To enter a number, press that number on the keyboard. If there is already a number in that square, it will be overwritten. Sudoku is a Number Puzzle that requires no mathematical knowledge. (no adding or multiplication). It is based upon Japanese style crosswords where you are required to use logic to place numbers onto a 9x9 grid. Puzzles " Confirmed" are fully resolvable by " Inclusion" and " Exclusion" while admitting other methods.

Comment 2 by DougKreider. Made on the 31st May 2013. I am a brand new player of Sudoku. I had finished with the entire book of puzzles from beginner to hard and at the end are few 16X16 games but I do not know where to start. I will like to ask, which is the best method to play and enjoy this type of puzzles? To enter a pencil mark, press control, shift, or alt on your keyboard at the same time as pressing a number key. Comment 3 by Ana . Made on the 22nd Nov 2013. I have started playing 16 x 16 puzzles and they are awesome and challenging. I read somewhere that the diagonal line of numbers from top left corner to bottom right corner and also from top right corner to bottom left corner must also contain numbers 1 to 16 only. Is this correct with the above puzzles. Thanks

For a 9x9 puzzle to have precisely one solution, the initial entries need to include at least eight of the nine digits. The hexadecimal system is a numeral system with a base of 16, using Arabic numerals to represent the first ten numbers (0-9) and the letters A-F for the other six digits. The hexadecimal system is useful in computer science because it is easier to map the hexadecimal system to the binary than the decimal system. Tips for use

Sudoku became a world hit in 2005. When measuring its popularity in enigmatic world, it is the biggest phenomenon since Rubik's Cube in the '80s. To solve the puzzle you must make sure that every column, row and 3x3 box contains the numbers 1 through to 9. Elimination: Determine what numbers cannot be in a square and eliminate them as possibilities, making it easier to see what can be placed there. Grid Structure: The puzzle consists of a 16x16 grid, which is further divided into 4x4 subgrids or regions. We recommend that you use Google Chrome because it's fast and easy to use when solving puzzles having 256 squares as well as for receiving different solutions and hints sent by the server.Instead of using only the digits 1 to 9, the hexadoku sudoku uses the 16 digits of the hexadecimal base: