There's no need for maths with Sudoku. Each horizontal line, each vertical line and each 3x3 square needs to contain the numbers 1 to 9, once and only once. Sounds simple? Well the rules are but is it as easy to solve?

Use your mouse to click on the black numbers on the left, then drag the number on to the main grid on the right. When you think you have completed the grid click on the "Submit" button to see if you're correct and find out the time it took to complete.