Sudoku. Sudoku, or Su-doku, is a Japanese fun puzzle game. Sudoku uses numbers, but no mathematics is needed, and that is why, it is so popular. If you are looking for Sudoku free games, search no more. Over www.sudoku.name you can find thousands of online Sudoku puzzle games that you can play for free. All you need to do is to learn the rules ... There are more than a few techniques to solve a Sudoku puzzle, but per Conceptis Puzzles, the easiest way to a Sudoku solution is to, “ Scan rows and columns within each triple-box area ...Sudoku puzzles come prefilled with numbers in some of the cells. They are ranked by a difficulty level which corresponds with how many numbers come pre-filled in the puzzle. The higher the difficulty the fewer prefilled numbers you will have. The ratings go from one star (easiest) to five stars (hardest). Expert level Sudoku. Expert Sudoku is a game for experienced Sudoku players with a very high level of difficulty. This hardest Sudoku puzzle is characterized by the fact that only a few numbers are shown in the Sudoku square, which consists of 9 small squares, where the cells are located 3x3. Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook.Sudoku Kingdom. Hello, Guest! Sudoku Kingdom Registration . Home - Classic Sudoku. Daily Sudoku. Beginner - Very easy sudoku. Feedback - Comments. Downloads puzzle and solution. Rules. Tutorial. Faq. Puzzles of last week. Register - Create an account. Login. You did not submit the 'Desired login name' field. This is a required information! Apr 17, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. Easy Sudoku level is perfect for beginners and children. Solving simple Sudoku puzzles online at sudoku.com is free. Useful tips and hints on the website will help You to …Our free online version of web Sudoku follows in the number puzzle's classic tradition, no pen or pencil needed! As you start the puzzle you can choose your Sudoku difficulty. We offer Sudoku for beginners, medium Sudoku, and Sudoku for experts. Additionally, the puzzle is updated every day giving you a new Sudoku challenge each and every day!Along with the original Sudoku game grid, you must also now fill the diagonal spaces in the middle - no overlaps! This makes for a challenging and fun puzzle that is sure to keep you entertained. This version of Sudoku from AARP Games allows you to play the game diagonally instead of up and down. Come back everyday for a fresh new puzzle.Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook. About Sudoku: Sudoku means 'Number Place'. It is made of 9 rows, 9 columns and 9 blocks. The goal is to place the numbers 1 to 9 in each row, column and block (a subgrid of 3x3 cells). Sudoku - Rules of the games: Each of the nine blocks has to contain the numbers 1 to 9 in its squares. Each number can only appear once column, row or 3x3 box. Draw/Play. Click the "today" button to play today's Daily Sudoku online. Click a square and enter numbers using the keypad. Use the space bar or delete to empty a cell. Add and remove "pencil marks" by holding down the <Ctrl> or <alt> key. Input a puzzle, or partially completed puzzle, and click "Print" for a printable page.Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck! Jogue Sudoku Gratuitamente Agora! O Sudoku é um dos jogos de quebra-cabeças mais populares de sempre. O objetivo do Sudoku é preencher uma grelha de 9x9 com números para que cada fila, coluna e secção 3x3 contenha todos os dígitos entre 1 e 9. Sendo um jogo de lógica, o Sudoku é também um excelente jogo para o cérebro. 710. 5680. Mar 27, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print.The EBook contains 48 sudoku puzzles with solutions and will be sent by email. Join here! Players with the same score are displayed in random order. In order to give equal chance to all players, the ranking table is cleared at the beginning of each month. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels ... Apr 17, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook. Sudoku puzzles come prefilled with numbers in some of the cells. They are ranked by a difficulty level which corresponds with how many numbers come pre-filled in the puzzle. The higher the difficulty the fewer prefilled numbers you will have. The ratings go from one star (easiest) to five stars (hardest).Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Play Lovatts Free Daily Online Sudoku. To solve Sudoku, every number from 1 to 9 must appear in: A new version of this puzzle is coming soon. PLAY THE BETA VERSION →. Click/Tap the pencil icon to toggle between the practice-number panel and the correct-numbers panel. Click/Tap a square to highlight it then use the number panel to …In 2014, we introduced The Mini Crossword — followed by Spelling Bee, Letter Boxed, Tiles and Vertex. In early 2022, we proudly added Wordle to our collection. We strive to offer puzzles for all ...Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook Extreme Sudoku is the most challenging version of the 9x9 grid puzzle game for the real puzzle masters! It's not just about following the basic rules - you've got to be a puzzle-solving expert and use advanced strategies to crack it. Extreme Sudoku level provides players with very few given digits and requires them to push their mental limits ...Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.I varje Sudoku-pussel har du ett nät med 9 x 9 rutor, uppdelade på nio 3 x 3 kvadratiska regioner (du kan se ovan för att få ett intryck av hur det ser ut). Så varje rad, kolumn eller region innehåller nio celler. När du startar ett Sudoku-pussel är några celler redan siffror ifyllda. Du kan inte ändra dessa siffror. 4112. Apr 22, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. How to play Killer Sudoku. Fill all rows, columns, and 3x3 blocks with numbers 1-9 exactly like in classic sudoku. Pay attention to the cages – groups of cells indicated by dotted lines. Make sure the sum of numbers in each cage is equal to the number in the upper left corner of the cage. Numbers cannot repeat within cages, a single row ... Enter the numbers of the puzzle you want to solve in the grid. You can solve the puzzle completely, partially or solve a single cell using the buttons in the Solving section of the Features block. Button: Solve Cell. Solves the cell of your choice. Click in the cell you want to solve first, then click this button.Sudoku is a puzzle game that involves filling in a grid of numbers so that each column, row, and region contains all the digits from 1 to 9. The grid is divided into nine smaller grids called "regions," and each region must also contain the digits 1 through 9. To solve a sudoku puzzle, you must use logic and eliminate possibilities until you ... Apr 22, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. Pick a date on the calendar and enjoy fresh sudoku puzzles every day! Come back to our puzzle kingdom of Sudoku every day and complete Sudoku game of the day. 🔢 Sudoku app features: More than 12000 well-formed classic sudoku puzzles with numbers 6 levels of difficulty: Fast Sudoku, Easy Sudoku, Medium Sudoku, Hard …24/7 Sudoku's Easy Sudoku puzzles are for all beginner sudoku players and those seasoned players looking for a quick and fun game. Sudoku is a relatively easy game to play and 24/7 Sudoku's awesome site makes it even easier to see and enjoy this great popular puzzle game! Sudoku is played by entering the digits 1 through 9 into each 3x3 …About Sudoku: Sudoku means 'Number Place'. It is made of 9 rows, 9 columns and 9 blocks. The goal is to place the numbers 1 to 9 in each row, column and block (a subgrid of 3x3 cells). Sudoku - Rules of the games: Each of the nine blocks has to contain the numbers 1 to 9 in its squares. Each number can only appear once column, row or 3x3 box.Registration to SudokuKingdom.com is completely free.Once registered you'll be able to participate the monthly ranking table. Desired login name *. Password *. Retype Password *. Email address *. Country (optional) Enter the characters displayed in the image. Sudoku Kingdom Membership Form. Sudoku.com offers free printable Sudoku puzzles of different difficulty levels to suit any skill level. Puzzles range from easy to evil, ensuring that both beginners and advanced players will find a challenge. Easy level printable Sudoku puzzles are perfect for beginners. They contain more numbers on the playing field than medium or hard levels ... Our free online version of web Sudoku follows in the number puzzle's classic tradition, no pen or pencil needed! As you start the puzzle you can choose your Sudoku difficulty. We offer Sudoku for beginners, medium Sudoku, and Sudoku for experts. Additionally, the puzzle is updated every day giving you a new Sudoku challenge each and every day!Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android. Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Leave blank to select a random puzzle. For Squiggly Sudoku and Sudoku-X, get Web ... In each Sudoku puzzle you have a 9x9 grid, divided into nine 3x3 square regions (you can just look above to get an impression). So each row, column or region contains nine cells. You start a Sudoku puzzle with some cells already filled in with numbers. You can't change these numbers. The more cells are pre-filled the easier the puzzle. The goal of Sudoku is to fill the cells with numbers from 1 to 9. The numbers are placed in 9 squares, 3x3 each, thus, in each row, in each column and in each small square there are 9 cells. The same digit can be used only once in each separate column, each line and in each small square. The level of difficulty depends on how many digits are ... Our new interactive Sudoku Solver will take you step by step through the process of solving a Sudoku puzzle using up to 36 different methods. Whether you are just starting or a seasoned expert, there will always be something for you on this site. Our lively forums host discussions of various techniques and answer your puzzle related questions.Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!The goal of Sudoku is to fill the cells with numbers from 1 to 9. The numbers are placed in 9 squares, 3x3 each, thus, in each row, in each column and in each small square there are 9 cells. The same digit can be used only once in each separate column, each line and in each small square. The level of difficulty depends on how many digits are ...Sudoku puzzles come prefilled with numbers in some of the cells. They are ranked by a difficulty level which corresponds with how many numbers come pre-filled in the puzzle. The higher the difficulty the fewer prefilled numbers you will have. The ratings go from one star (easiest) to five stars (hardest).Sudoku is a game of logic and strategy, where you have to fill in the blank squares with numbers from 1-9 in order to complete the puzzle. The game can be tricky at times but it's definitely worth the challenge! Sudoku is one of the most popular games out there, and it's a great way to engage your mind. Sudoku is the hottest game in America!The best Sudoku players in the world are amazingly fast at working through the grid. Play daily advanced web sudoku puzzles online on Sudoku.com. Expert sudoku level is …Sudoku Kingdom. Hello, Guest! Sudoku Kingdom Registration . Home - Classic Sudoku. Daily Sudoku. Beginner - Very easy sudoku. Feedback - Comments. Downloads puzzle and solution. Rules. Tutorial. Faq. Puzzles of last week. Register - Create an account. Login. You did not submit the 'Desired login name' field. This is a required information!Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!5 days ago · LiveSudoku is one of the first fully playable online sudoku experiences. Created in 2006, our puzzles stand out as the best choice for anyone looking for a fun and challenging Sudoku experience. While competitors like Pogo, AARP, Washington Post, and the New York Times may offer their own daily Sudoku puzzles, we believe that our puzzles stand ... Sudoku puzzle app ”Sudoku Kingdom - Sudoku puzzle” is a Sudoku puzzle game in which you solve various Sudoku puzzles to get the crown and aim for the highest rank. Sudoku Daily Challenge adds one special Sudoku puzzle per day. You will also get a gorgeous collection when you complete a month's worth of Sudoku Daily …348. 2784. Apr 15, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print.Free daily Sudoku games from the Los Angeles Times. Check back each day for a new puzzle or explore ones we recently published.Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print.Free daily Sudoku games from the Los Angeles Times. Check back each day for a new puzzle or explore ones we recently published.Sudoku Academy is a completely free platform for playing sudoku, with no limits on the number of games you can play. We offer a vast selection of sudoku puzzles across 5 different difficulty levels, ensuring that there is something for players of all skill levels. To keep the site running smoothly and continue to add new features, we do display ...333. 2664. Apr 13, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print.Sudoku is a puzzle game that involves filling in a grid of numbers so that each column, row, and region contains all the digits from 1 to 9. The grid is divided into nine smaller grids called "regions," and each region must also contain the digits 1 through 9. To solve a sudoku puzzle, you must use logic and eliminate possibilities until you ...Enter the numbers of the puzzle you want to solve in the grid. You can solve the puzzle completely, partially or solve a single cell using the buttons in the Solving section of the Features block. Button: Solve Cell. Solves the cell of your choice. Click in the cell you want to solve first, then click this button.Sudoku puzzle app ”Sudoku Kingdom - Sudoku puzzle” is a Sudoku puzzle game in which you solve various Sudoku puzzles to get the crown and aim for the highest rank. Sudoku Daily Challenge adds one special Sudoku puzzle per day. You will also get a gorgeous collection when you complete a month's worth of Sudoku Daily …Sudoku Online offers different levels of sudoku puzzles, from easy to very hard, that you can play online or print for free. Sudoku means 'Number Place' and the goal is to place … 4112. Apr 22, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. Apr 17, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.The EBook contains 48 sudoku puzzles with solutions and will be sent by email. Join here! Players with the same score are displayed in random order. In order to give equal chance to all players, the ranking table is cleared at the beginning of each month. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels ...362. 2896. Apr 16, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print.Evil sudoku is a master game level for experienced players and sudoku fans. Play evil sudoku online on Sudoku.com website to train your brain and have fun!Sudoku. Sudoku is a logic puzzle game. The objective is to fill the 9x9 Sudoku grid with digits from 1 to 9 such that each of these 9 digits appears in each row, each column and each 3x3 block once and only once. Play Sudoku Online. Billions of free Sudoku puzzles of varying difficulty levels are offered here online.Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.Start by choosing the type of sudoku you want to print: 9x9 sudoku, 4x4 sudoku or 6x6 sudoku. Then select the level of difficulty: easy, medium, hard, expert, evil. For 9x9 sudoku you can choose to print 4 sudoku per page or 6 sudoku per page. Then choose the print format: PDF or HTML.Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.Play Sudoku Online: solve unlimited free sudoku puzzles from easy, medium, hard and evil difficulty levels. Play it and challenge yourself.362. 2896. Apr 16, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print.Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook.Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.
SUDOKU - TheSudoku.com Sudoku game. Never-ending variety of free online Sudoku puzzles - you can play your daily Sudoku here, get a printable Sudoku or enjoy all the …. Future tools
Apr 17, 2024. Solved puzzle score: Easy=1 point Medium=2 points. Hard=4 points Very hard=8 points. *** Show Full Player Ranking Table ***. Sudoku Kingdom, Free online sudoku puzzles. Train your brain with 4 difficulty levels, Easy, Medium, Hard and Very Hard sudoku to Play and Print. Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android. Sudoku puzzles come prefilled with numbers in some of the cells. They are ranked by a difficulty level which corresponds with how many numbers come pre-filled in the puzzle. The higher the difficulty the fewer prefilled numbers you will have. The ratings go from one star (easiest) to five stars (hardest).If you are a frequent user here you probably know the great ease in which the game is set in our sudoku kingdom. For you the new visitor, a great feature we have is called highlight digit, which highlights the digit you want across the whole grid, making it very eye-friendly to spot that eluding empty cell. For the advanced sudoku games, you can …2 days ago · Sudoku Evil is a very hard level of sudoku for expert players. You can play online, print, or join the sudoku kingdom community and compete in the arena. Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook.Each Sudoku has a unique solution that can be reached logically without guessing. Enter digits from 1 to 9 into the blank spaces. Every row must contain one of each digit. So must every column, as must every 3x3 square. Play Offline with Web Sudoku Deluxe. Download for Windows or Mac OS X. Print a Customized Sudoku Ebook.Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Here is the puzzle. Good luck!Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android.Play unlimited sudoku puzzles online. Four levels from Easy to Evil. Compatible with all browsers, tablets and phones including iPhone, iPad and Android. Look for rows, columns and 3×3 boxes with just a few blanks remaining. Try adding numbers which already appear often in the Sudoku puzzle. After entering a number, check to see where else it has to go. For trickier puzzles, click Options to turn on pencil marks. Leave blank to select a random puzzle. For Squiggly Sudoku and Sudoku-X, get Web ... I varje Sudoku-pussel har du ett nät med 9 x 9 rutor, uppdelade på nio 3 x 3 kvadratiska regioner (du kan se ovan för att få ett intryck av hur det ser ut). Så varje rad, kolumn eller region innehåller nio celler. När du startar ett Sudoku-pussel är några celler redan siffror ifyllda. Du kan inte ändra dessa siffror. Popular methods and techniques for solving hard web Sudoku. Print difficult Sudoku and use different colors and symbols to solve it. This way, you can track whether certain numbers have already been used with color. Symbols can mark solutions based on others. You can also use the online notes feature on Sudoku.com. .