Rdlc report total issue


On my report i have 2 tables which prints items and resources. And in those tables i also have unit prices and the total of unit price at the table footer. My issue however, is that when i'm trying to calculate the total of itemUnitTotal + ResourceUnitTotal and prinit it to a textbox almost my result is double up, i get wrong result. Does anyvody have a better way of solving this issue?