In the following sum the digits 0 to 9 have all been used, O = Odd, E = Even, zero is even and the top row's digits add to 9. Can you determine each digit?

The digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 can be arranged into an addition sum to add up to almost any total, except that nobody has yet found a way to add up to 1984.
However 9 digits can equal 1984 by an addition sum.
Which digit is omitted?

Arrange all the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 to give four different square numbers. (You make a square number when you multiply something by itself, so 49 is square because it is 7 times 7)