尝试下面

 = SUM（CINT（字段！vehicles.Value））

i have a report in which i want to add column value.like

Name          vehicles
sa               23
wa               22
xc               10
Total:           55

i have created one row outside the group, and the textbox which is below vehicle column i put an expression like

=Sum(Fields!vehicles.Value)

But its gives error,on the other end if i put Count instead of Sum it return 3,what is the problem is here?

try below

=Sum(CInt(Fields!vehicles.Value))