Mr Cheong had $ $$r$$. He gave the money equally to his three children, Calvin, Catherine and Candice. Catherine saved $250 of the money and spent the rest of it. <hr> If $$r$$ = 900, find the amount of money that Catherine spent. <hr> <input min="0" type="number" id ="imp6pg019q9b_1" class="lineinput" placeholder="?" />