Adding Summary Elements

I have added query based tabs for change orders to my Contract SOV.   I am able to create a summary element to total the change orders.  But I would like to add the total change orders and original contract amount to arrive at the revised contract amount.  I have several calculations that I would like to do which would use summary data elements.      I can create a Query Based Data Element, but previous documentation limited these to 5.  Is 5 still the limit?  Or is there a another way to do that?