Nasty Nines

It is a cube of nine squares. Numbers are inserted in some of the squares. To solve the puzzle, you must fill in the remaining squares. To determine what numbers to insert, you must follow the pattern set by the numbers given. Some cubes have only one missing number, some two missing numbers, and the hardest to solve have 3 missing numbers.

The pattern may add, subtract, multiply or divide the number in the square before it. You must first determine whether the pattern goes across (horizontally) or down (vertically). The pattern will be the same in each row across OR in each column going down. You must decide whether the pattern goes across or down by looking at the numbers given.