Summing a Range of Grades

I've got grades A+ through F which I've assigned a numerical value in a table. I would like to sum those grades using the table as the reference. I know that I could use a sumproduct but I'm think there has to be a quicker way using a vlookup or index. I've attached a sample sheet. Any help would be greatly appreciated.Grade Calculation Sample.xlsGrade Calculation Sample.xls