Sudoku
Sudoku puzzles are solved by logic and no math is required. As seen on the right, it consists of a grid which is usually made up of nine rows, nine columns, and nine boxes that are separated by thicker, darker lines. Some of these boxes will contain numerals from 1 to 9. To solve the puzzle, a person must fill in all the empty squares without using the same numeral twice in each column, row, or box, and without changing the numerals that are already in the grid.