Unknown008's neat trick of borrowing from the tens column is the only way to solve this problem. If borrowing is not allowed then the problem has no solution.
In fact, each number in the top row would then have to be the sum of the two numbers below it. But an odd number must be the sum of an odd number and an even number; and an even number is either the sum of two even numbers or the sum of two odd numbers. That means that each column must contain either two odd numbers or no odd numbers. Therefore the total number of odd numbers in the square must be even. But there are five odd numbers in the set 1, ..., 9, and five is not an even number. So there is no possibility to fill the square in the required way (except by using the borrowing trick).