# 3 Ways to Solve Sudoku

Do you want to try to solve a Sudoku puzzle but don't know where to start? This puzzle looks very complex because it involves numbers, but it doesn't actually involve any mathematical process. Even if you think you are a "landslide" in math, know that you can still be able to play Sudoku. In fact, you can replace the numbers with letters or symbols, obtaining the same result; it's just a matter of recognizing the puzzle pattern. Start learning the elementary rules and then move on to techniques for beginners and experts.

## Steps

### Method 1 of 3: Understanding the Basics

#### Step 1. Learn the pattern

The traditional sudoku is made up of a table of 9 large squares, each of which is divided into 9 smaller boxes; when you look at the puzzle, you can see that some of these boxes have numbers from 1 to 9. The more complex sudokus have few numbers.

### Larger squares are often surrounded by a bold border, while boxes are defined by thin lines; besides, the big ones can be colored just like a chessboard

#### Step 2. Align the rows and columns

One of the basic rules is that within each row and each column there must be all the numbers from 1 to 9 without repetition.

#### Step 3. Pay attention to the numbers of the large squares

Also in this case, all the numbers from 1 to 9 must appear within each sector. Each digit must appear only once, since each square is made up of 9 boxes.

### If the number "2" appears in a large square, you can be sure that there cannot be another in the same sector

#### Step 4. Use a pencil instead of a pen

Since you are a beginner in this game, you are likely to make mistakes and, if you use a pen, you may mess with the diagram; opt for the pencil to be able to erase what you write.

#### Step 1. Look for a square with only one empty square

Inspect the whole table to see if there is a sector that is missing only one number and fill it with the correct digit (from 1 to 9) proceeding by exclusion.

### For example, if you can read the numbers 1 to 3 and 5 to 9 in a large square, you know for sure that 4 is missing and you can write it down in the blank box

#### Step 2. Check each row and column for a single blank box

Slide your finger along each horizontal or vertical row to find a single free space; if so, note which number is missing and write it down.

### If in a column there are the numbers from 1 to 7 and 9, only the 8 is missing and you can write it in the corresponding box

#### Step 3. Keep checking the columns and rows to complete the larger squares

Look at a row of three large sectors and look for a number that is in two different squares. Slide your finger on the rows that contain this figure: the third sector must also show it, but it must not be in the two rows you just traced; it must necessarily be in the third line. Sometimes there are two numbers that occupy the other boxes, so you can easily write the value in question in the only one remaining.

### If you can read the number 8 in two sectors, look for the same digit in the third square. Run your finger along the lines that contain each 8, as you know for sure that that number cannot be in the same lines as the third sector

#### Step 4. Check in the opposite direction

Once you have checked the table by rows or by columns, repeat the operation in the perpendicular direction. Consider the previous example but with a slight difference; suppose that, when you get to the row of the third square, there is only one square already occupied.

### In this case, you cannot know exactly in which of the two free boxes you can write the figure, but you can proceed by exclusion by checking the columns. If the number is already present in a column, you know for sure that you cannot repeat it and you have to write it down in the other available box

#### Step 5. Proceed by groups of numbers

This means that if a digit is repeated often, you can try to fill in the boxes where the missing repetitions should be. If the table has so many 5s, check the pattern to try to place as many missing 5s as possible.

### Method 3 of 3: More Complex Techniques

#### Step 1. Look at a series of three large sectors

Another method involves analyzing three squares in a row or column; choose a number and see if you can put it in all three.

### For example, consider number 6. Check which rows or columns already contain it and use them to inspect three large sectors. Based on the information you have and the numbers already in the pattern, try to enter as many of the other 6 as possible

#### Step 2. Write the numbers in pencil

As the puzzle becomes more complex, you may realize that the techniques described are not always sufficient to solve it; in this case, you have to hazard a solution and fill in the boxes with hypothetical numbers. When considering a possibility, write the small figure in the corner of the box using the pencil; you may even end up writing 3-4 tentative numbers as you solve the quiz.