What are the numbers for? Each number tells you how many numbers group together to form one group.
Move your mouse over the puzzle to see the answer.
The numbers indicate how many squares are in each group. Initially you may be given more than one number in a particular group. Groups with the correct number of squares in them are shaded.
Groups with the same number are not allowed to touch, otherwise they'd form a group with a larger number. This group would contain more squares than the number in each square so would no longer be shaded.