Kakuro Numbers Game

In this math game you begin with a random grid of blank squares. A series of squares connected either vertically or horizontally form a group and before each group is a block with a number on it. The objective of this game is to fill in the squares with numbers from 1 to 9 so that the numbers in the groups do not repeat and that the numbers sum up to the number before the group. The faster you finish the game, the higher your score. When you are stuck, you can click the hint button to get some hints, but you will suffer a time penalty.