Access Reports in XP

I have a table with four columns in which I’ve listed donations made by individuals. Each entry has a batch Number assigned. I’ve run a query on the table to get the total for each heading (Donations, Luminaries, Team Regisitration, Corporate Sponsor) and each of those sum in the query. I developed a report to cover these and get the information to come over.
What I can’t get is a formula that will total the four columns together as a grand total.
Closet I’ve got is a #error. Most time it display nothing.
Formula I entered is =[Donation]+[Luminaries]+[Team Registration]+[Corporate Sponsor]

Any suggestions