Need to find the Average of percentages & Switch for Grades

Question

Hi ,

        In our application we are generating a crosstab rdlc report,In that we are dispalying percentage of marks in each category. Now at the end of  each row for a person we have to give grade by calculating the average of percentages displayed in other columns of the report. As we are not using any groups,  so we can't use aggregate functions.

          So I tried using expressions ,given some thing like as follows

 

Switch((Fields!Cream_Mbrt.Value+Fields!Butter_Milk_Mbrt.Value+Fields!Butter20Kg_Coliforms.Value+Fields!Butter_ConsPack_Coliforms.Value+Fields!Ghee_Sensory_Evaluation.Value+Fields!Market_Complaints)/6 >90 ,"A",

(Fields!Cream_Mbrt.Value+Fields!Butter_Milk_Mbrt.Value+Fields!Butter20Kg_Coliforms.Value+Fields!Butter_ConsPack_Coliforms.Value+Fields!Ghee_Sensory_Evaluation.Value+Fields!Market_Complaints)/6 >80 ,"B",

(Fields!Cream_Mbrt.Value+Fields!Butter_Milk_Mbrt.Value+Fields!Butter20Kg_Coliforms.Value+Fields!Butter_ConsPack_Coliforms.Value+Fields!Ghee_Sensory_Evaluation.Value+Fields!Market_Complaints)/6 >60 ,"D",

(Fields!Cream_Mbrt.Value+Fields!Butter_Milk_Mbrt.Value+Fields!Butter20Kg_Coliforms.Value+Fields!Butter_ConsPack_Coliforms.Value+Fields!Ghee_Sensory_Evaluation.Value+Fields!Market_Complaints)/6 >60

and Fields!Cream_Mbrt.Value+Fields!Butter_Milk_Mbrt.Value+Fields!Butter20Kg_Coliforms.Value+Fields!Butter_ConsPack_Coliforms.Value+Fields!Ghee_Sensory_Evaluation.Value+Fields!Market_Complaints)/6 > 0 ,"F"

)

 

but getting error that value in the textbox has '+'...........blah..blah.........................

 

Actually we are new to rdlc reports, please give us any suggestions to resolve......