How to setup sudoku

As a new sudoku player, you're going to make mistakes, and with a pen, you'll end up with a mess of a board. Instead, use a pencil so you can erase mistakes. Remember to press lightly so you can erase mistakes better. Method 2. Look for a single empty in a larger square.

Check each square to see if it has a single square open. If it does, it's easy to fill in. Just figure out what number is missing from 1 to 9. Check for singular empty squares in the rows and columns. Run your finger down each row and column to see if any of them only have 1 square open. If a row does, figure out which number from 1 to 9 is missing in that row or column and fill it in.

Scan rows or columns to fill in larger squares. Look at a row of 3 large squares. Check for a number that's repeated 2 times in different squares.

Run your fingers along the rows that contain that number. The third large square must contain the same number, but it can't be in 1 of the 2 rows you're tracing. It must be in the third row. Sometimes, 2 other numbers will be in that row, so you can easily fill in the number you're scanning. Run your finger down the rows with each "8," as you know the "8" can't be in those rows in the third large square.

Add the opposite direction. Once you've got the hang of scanning across just rows or columns, add the other direction as well. Take the previous example with a slight difference. When you get to the third square, it only has 1 number filled in in the open row.

See if the number you're trying to fill in is in 1 of the columns. In that case, you know it can't go in that column and must go in the other one. Work in groups of numbers. That is, if you see that you have a lot of one number on the board, it can help to start trying to fill in the rest of that number.

Say you have a large number of 5s on the board. Use your scanning techniques to fill in as many 5s as you can. Method 3. Look at a set of 3 large squares. Another option is to include 3 of the large squares in a row or column in your analysis. Pick 1 number, and see if you can place it across all 3 squares.

Based on that information and what you have in the squares, try to place as many of the 6s as you can. Pencil in numbers. As puzzles get more difficult, you'll find that just using the above techniques won't always solve the puzzle. In those cases, you need to start filling in what numbers could possibly go in each square. When you get a possibility, place it in the corner of a small square in pencil. You may have as many as 3 or 4 numbers penciled in as you try to solve the puzzle.

Recheck often. As you fill in numbers, go back over the puzzle to figure out spaces you had to leave blank before. Once you've filled in new numbers, you may be able to figure out those spaces. As you recheck the blank spaces, go through the techniques again to help fill in numbers. Sample Intermediate Sudoku. Sample Hard Sudoku. Yes, unless the puzzle was printed with an error, which is unlikely.

Not Helpful 19 Helpful When all of the squares are the correct numbers, can I assume the rows and columns are correct? The numbers in the 9 squares cannot be "correct," as you say, unless the rows and columns are also correct. You can have all 9 squares with all 9 numbers, but that does not guarantee that the rows and columns will be correct. Not Helpful 13 Helpful Once you get the hang of it, it will become pretty easy and fun.

The easiest way to test your puzzle is to enter the puzzle manually into a game like Sudoku Dragon mentioned above. Click the Show button. If you get an error message, you do not have a valid puzzle. Re-enter the removed number pairs and try again. Repeat step 2 and step 3 until you can no longer remove mirror pairs without an error or creating an invalid puzzle that has multiple solutions.

This book explains in detail how to program Sudoku. Complete source code is given. Grading Sudoku Puzzles Ever wonder how grading Sudoku puzzles is done? My research has revealed what Sudoku patterns you are likely to find in different grades of puzzles and games. Many solvers pencil in candidates and look for common…. Read More ». Download this free Sudoku worksheet to help you solve all of your Sudoku puzzles.

This handy Sudoku Excel template will allow you to enter and remove…. Sudoku Solver Review Use a Sudoku solver to solve your most difficult sudoku puzzle instantly! You have several Sudoku solvers from which to pick. You must be logged in to post a comment.

Use an online generator. If making a Sudoku puzzle by hand gets too frustrating, check out an online generator. There are many different websites that can help you generate and check your puzzles.

Method 3. Begin removing digits. With an eraser, begin by erasing one number from each column, row and 3x3 square. The more you erase, the harder the puzzle will be to solve, so think about how difficult you want the puzzle to be.

Also, consider making a copy of your solution to reference. Check to make sure your puzzle can be solved. With each digit that you erase, work through the puzzle to make sure it can still be finished.

Erase blank squares and ink filled ones. Copy and share your puzzle. Make some copies of your finished puzzle at home or in a copy shop. Next, share it with your friends and family members. Get some feedback about the difficulty of your puzzle, then practice making a few more.

Support wikiHow and unlock all samples. Sample Intermediate Sudoku. Sample Hard Sudoku. You could create a site with free sudokus and put ads on the site. You could also use ad. Or, simply make a large collection of them and sell as a printable PDF for a certain amount of money.

Not Helpful 7 Helpful You can try it out and see if you can solve it correctly. If not, you will realize where there are errors and be able to correct them. Not Helpful 11 Helpful 8. Logan Eichfeld. This depends on how difficult you want your puzzle to be.

If you want your puzzle to be easy, remove a small amount of numbers from the grid. If you want your puzzle to be intermediate, then remove a moderate amount of numbers from the grid. Not Helpful 47 Helpful In some cases, a Sudoku puzzle can have two solutions, so it definitely is possible. It's just more common for them to have one. Not Helpful 16 Helpful 7. There are 6,,,,,,, distinct ways to fill the sudoku grid, ignoring symmetries, rotation, etc.

If you eliminate solutions that look different but are functionally identical, 5,,, distinct ways to fill the grid remain. The number of actual puzzles you could construct from these grids is essentially limitless. Not Helpful 3 Helpful Ascot Ng. You can probably still claim it because there are 6,,,,,,, puzzles that are possible. Not Helpful 1 Helpful 5. Include your email address to get a message when this question is answered. Some use larger boards, the alphabet, or symbols, and they all help keep the game fresh.

Helpful 0 Not Helpful 0. Handmaking a sudoku puzzle can be a little tricky at first, because the numbers have to be perfectly placed. However, with more practice, it will become easier and easier. Get help with sudoku checkers.

If you ever get stuck while making your puzzle, use an online checker to make sure that your puzzle is solvable and within the rules. Submit a Tip All tip submissions are carefully reviewed before being published.