Chat

How to Make a Sudoku using Fill and Remove Method

Step 0:

Step 1 - The first step is to fill the grid with numbers. The default sudoku is blank. Type a number to the blank squares, or drag a digit from the top of the sudoku and place it to a blank square. You may also drag the eraser (to the left of all digits) to erase a filled square.
after your digit is placed, a hint will be given. For example, "Number in R1C3 is NOT between 1 and 9." meaning that the digit you filled in the square at the first row and the third column is not a number. Or "Error: Row 1 contains more than one 2. " meaning that the digit just filled making the first row containing more than one number 2s and you need to correct that.
You may load a saved sudoku by clicking "Load".
You may change the sudoku grid appearance by clicking "Appearance".
You may clear the entire grid by clicking "Clear the Grid".
You may add notes to the Sudoku by clicking "Notes".
You may save the Sudoku by clicking "Save".
You may get help from the computer to fill all the numbers by clicking "Help".

When you finished filling a number to all the squares with all constraints satisfied, click "Next", and go to Step 2.
The first picture below shows the almost empty grid with only three numbers filled.
The second picture below shows the grid is fully filled and ready to go to Step 2.

Step 2 - The second step is to remove numbers. Every time two numbers removed (numbers from two symmetrical squares). If a removal is invalid (i.e., the removal makes the Sudoku has at least two solutions), the removal will not be done. If a removal is valid, two numbers removed. When at least 30 numbers removed, click "next" to go to step 3.
You may change the sudoku grid appearance by clicking "Appearance".
You may add notes to the Sudoku by clicking "Notes".
You may save the Sudoku by clicking "Save".
You may get help from the computer to remove at least 30 numbers by clicking "Help".
The first picture below shows some of the numbers are removed.
The second picture below shows over 30 numbers are removed and ready to go to Step 3.

Step 3 - Step 3 - Done step. You may change the sudoku grid appearance by clicking "Appearance".
You may add notes to the Sudoku by clicking "Notes".
You may save the Sudoku by clicking "Save".
You may restart making a new Sudoku by "Make Another Sudoku".
The first picture below shows some of the numbers are removed.

Help Center - How to Play a Sudoku?

This article answers questions: How to type or drag numbers to a blank spare? How to Customize or Personalize Sudoku Grid? How to Load an Indexed/Calendar Sudoku? How to Load a saved Sudoku? How to load a Sudoku in image format? How to get help of solving or making this Sudoku? Etc.