CroossGames21 is a Blog and a WEB site with free, on-line and interactive cross numbers games and cross words games. The Sudoku is the most popular and well-known mathematical game in the world, so we start our posts with this game, in different leves, and suggesting different variants. Many of the cross numbers games and…
This article explains how to play Castling game and details how you can solve it. The general rules of the Sudoku board 9×9 can be seen in the post The Sudoku Game, click here to go there. To play Castling, click here. Castling is a Cross Game 21 game, easy and fast to play. Its…
This article explains how to play Sudoku Classic and details how you can solve it. The general rules of the Sudoku game can be seen in the post The Sudoku Game, click here to go there. To play Sudoku Classic, click here. Daily Sudoku game is a different game that we publish every day to…
This article explains how to play Daily Sudoku and details how you can solve it. The rules of the Sudoku game can be seen in the post The Sudoku Game, click here to go there. To play Daily Sudoku, click here. Daily Sudoku game is a different game that we publish every day to all…
Terms of Service Privacy Policy Cookies Policy About us CrossGames21 was developed by P.Marshall, who has researched and developed algorithms for the construction and solution of brain teasers -including Sudoku- since the 90’s. With the development of the Internet, the massive dissemination of these games has been facilitated, also incorporating interactive, dynamic elements and colors,…
The origin of this game is due to the Swiss mathematician Leonhard Euler during the eighteenth century. However, it spread its fame in the second half of the 20th century, first in Japan, then spreading to the rest of Asia and the West. Its dissemination and mass use was mainly thanks to the publications of…
The games available on CrossGames21 are described below, explaining the characteristics of each one. Both standard sudoku games and new games from our website are included based on the Sudoku board. Standard Games Standard Sudoku games are preferred by the public. Many of our users have been addicted to solving Sudoku games in newspapers, magazines…
When we talk about levels we refer to the difficulty to solve a sudoku game. Among sudoku lovers we will find from beginners to expert scholars. This explains why all publications and applications disclose the level of difficulty, so that each player can choose the level they want to play at. Diffulty to solve Sudoku…
Menu buttons in Sudoku Games The menu options are located at the top above the game board. Each menu option is configured on a button. As you mouse over the menu, the buttons change color. The functionality of each button is described below. When clicking or touching some of these buttons (H&G, Guide and Pencil)…
In this article we explain some techniques to solve sudoku games, from the simplest to the most complex. 1. Unique number to place in a cell The first and easiest trick to solve the game is the unique number to place in a cell. Look at the examples in the diagram. In example 1, we…
