My class loves to do Sudoku. Of course, we do these together as a whole group, but it's different, and it works the brain in analytical ways to help them grow smarter.
The object is simple. Using just the numbers 1, 2, 3, and 4, each row and column has to have one of each number. The strategy I use is to find the rows with the fewest empty squares and solve them first. This makes the puzzle fill up faster and it gets easier to solve.
Below is the answer guide.